Merge pull request #1 from prashantsinalkar/masterHEADmaster

Initial commit

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diff --git a/Engineering_Physics_by_D_C_Ghosh/1-Classical_Mechanics.ipynb b/Engineering_Physics_by_D_C_Ghosh/1-Classical_Mechanics.ipynb
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+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 1: Classical Mechanics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.10: Common_velocity_of_a_car_truck_system.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex1.10: : Page-14 (2008)\n",
+"clc; clear;\n",
+"m1 = 1200;    // Mass of the car, kg\n",
+"m2 = 3600;    // Mass of the truck, kg\n",
+"u1 = 30;    // Speed of the car, m/s\n",
+"u2 = 20;    // Speed of the truck, m/s\n",
+"theta = 60;    // Direction of motion of the truck w.r.t. that of car, degree\n",
+"// As m1*u1 + m2*u2 = (m1 + m2)*v, solving for v along x and y directions\n",
+"v_x = (m1*u1 + m2*u2*cosd(theta))/(m1 + m2);    // Common speed along x-direction, m/s\n",
+"u1 = 0;    // The speed of the car after interlocking with the truck, m/s\n",
+"v_y = (m1*u1 + m2*u2*sind(theta))/(m1 + m2);    // Common speed along y-direction, m/s\n",
+"v = sqrt(v_x^2 + v_y^2);    // Common speed of the car-truck system, m/s\n",
+"theta = atand(v_y/v_x);    // Direction of common velocity w.r.t. that of car, degree\n",
+"printf('\nThe common speed of the car-truck system = %4.1f m/s', v);\n",
+"printf('\nThe direction of common velocity = %4.1f degree north of east', theta);\n",
+"// Result \n",
+"// The common speed of the car-truck system = 19.8 m/s"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.11: Velocity_of_third_piece_of_the_exploded_object.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex1.11: Page-14 (2008)\n",
+"clc; clear;\n",
+"v1 = 20;    // Velocity of first piece, m/s\n",
+"v2 = 30;    // Velocity of second piece, m/s\n",
+"// From conservation of momentum, in x-direction \n",
+"// m*v1*cosd(0)+m*v2*cosd(45)+m*v3*cosd(theta) = 0, solving for v3*cosd(theta)\n",
+"v3_cos_theta = -(v1*cosd(0)+v2*cosd(45));    // x-component of v3 along theta, m/s\n",
+"// From conservation of momentum, in y-direction \n",
+"// m*v1*sind(0)-m*v2*sind(45)+m*v3*sind(theta) = 0, solving for v3*sind(theta)\n",
+"v3_sin_theta = -(v1*sind(0)-v2*sind(45));    // y-component of v3 along theta, m/s\n",
+"theta = atand(v3_sin_theta/v3_cos_theta);    // Direction of velocity of third piece, degree\n",
+"v3 = -(v1*cosd(0)+v2*cosd(45))/cosd(theta+180);    // Velocity of third piece, m/s\n",
+"printf('\nThe velocity of third piece is %4.1f m/s towards %d degree north of west', v3, ceil(theta+180));\n",
+"// Result \n",
+"// The velocity of third piece is 46.4 m/s towards 153 degree north of west "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.5: Force_of_contact_between_two_masses.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex1.5: Page-11 (2008)\n",
+"clc; clear;\n",
+"m1 = 2;    // Mass of first body, kg\n",
+"m2 = 1;    // Mass of second body, kg\n",
+"F = 3;    // The horizontal force applied to the mass m1, N\n",
+"F_prime = m2/(m1 + m2)*F;    // Force of contact between m1 and m2, N\n",
+"printf('\nThe force of contact between m1 and m2 = %3.1f N', F_prime);\n",
+"F_prime = m1/(m1 + m2)*F;    // Force of contact when F is applied to m2, N\n",
+"printf('\nThe force of contact when F is applied to m2 = %3.1f N', F_prime);\n",
+"// Result \n",
+"// The force of contact between m1 and m2 = 1.0 N\n",
+"// The force of contact when F is applied to m2 = 2.0 N "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.6: Direction_of_motion_of_a_ball_after_momentum_conservation_during_collision.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex1.6: Page-12 (2008)\n",
+"clc; clear;\n",
+"v = 1;    // Let the speed of the ball B be unity, unit\n",
+"v_prime = v/2;    // Speed of the ball after the collision, unit\n",
+"theta = atand(v_prime/v);    // The direction of motion of the ball A after collision, degree\n",
+"printf('\nThe direction of motion of the ball after collision = %2.0f degree', theta);\n",
+"// Result \n",
+"// The direction of motion of the ball after collision = 27 degree "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.9: Angular_velocity_of_the_combination_of_two_wheels.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex1.9: Page-14 (2008)\n",
+"clc; clear;\n",
+"omega1 = 500;    // Angular speed of rotating shaft, r.p.m.\n",
+"omega2 = 0;    // Initial angular speed of the second wheel, r.p.m.\n",
+"I = 1;    // For simplicity assume moment of ineria of the wheels to be unity\n",
+"I1 = I, I2 = I;    // Moment of inertia of wheels A and B, kg-Sq.m\n",
+"// As I1*omega1 + I2*omega2 = (I1 + I2)*omega, solving for omega\n",
+"omega = (I1*omega1 + I2*omega2)/(I1 + I2);    // Angular speed of the combination of two wheels, r.p.m.\n",
+"printf('\nThe angular speed of the combination of two wheels = %3.0f r.p.m.', omega);\n",
+"// Result \n",
+"// The angular speed of the combination of two wheels = 250 r.p.m. "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Engineering_Physics_by_D_C_Ghosh/2-Electricity_and_Magnetism.ipynb b/Engineering_Physics_by_D_C_Ghosh/2-Electricity_and_Magnetism.ipynb
new file mode 100644
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+++ b/Engineering_Physics_by_D_C_Ghosh/2-Electricity_and_Magnetism.ipynb
@@ -0,0 +1,234 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 2: Electricity and Magnetism"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.12: Work_done_in_moving_a_particle_in_force_field.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex2.12: Page-80 (2008)\n",
+"clc; clear;\n",
+"t = poly(0, 't');\n",
+"x = t^2 + 1;\n",
+"y = 2*t^2;\n",
+"z = t^3;\n",
+"F = [3*x*y -5*z 10*x];    // Force acting on the particle, N\n",
+"t1 = 1;    // lower limit\n",
+"t2 = 2;    // upper limit\n",
+"dr = [derivat(x); derivat(y); derivat(z)];    // Infinitesimal displacement, m\n",
+"dW = F*dr;    // Work done or infinitesimally small displcement, J\n",
+"work_exp = sci2exp(dW);    // Convert the polynomial to the expression\n",
+"W = integrate(work_exp, 't', t1, t2);    // Total work done in moving the particle in a force field, J\n",
+"printf('\nThe total work done in moving the particle in a force field = %d J', W);\n",
+"// Result "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.13: Evaluation_of_force_integral.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex2.13: Page-80 (2008)\n",
+"clc; clear;\n",
+"x = poly(0, 'x');\n",
+"y = x^2-4;\n",
+"F = [x*y (x^2 + y^2)];    // Force acting on the particle, N\n",
+"x1 = 2;    // lower limit\n",
+"x2 = 4;    // upper limit\n",
+"dr = [derivat(x); derivat(y);];    // Infinitesimal displacement, m\n",
+"dW = F*dr;    // Work done or infinitesimally small displcement, J\n",
+"work_exp = sci2exp(dW);    // Convert the polynomial to the expression\n",
+"W = integrate(work_exp, 'x', x1, x2);    // Total work done in moving the particle in a force field, J\n",
+"printf('\nThe total work done in moving the particle in the x-y plane = %d J', W);\n",
+"// Result \n",
+"// The total work done in moving the particle in the x-y plane = 732 J "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.31: Electric_flux_through_a_surface_area.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex2.31: Page-93 (2008)\n",
+"clc; clear;\n",
+"E = [3 4 8];    // Coefficients of i, j and k in the electric field, N/C\n",
+"S = [0; 0; 100];    // Coefficients of i, j and k in the area vector, Sq. m\n",
+"phi_E = E*S;    // Electric flux through the surface, N-Sq.m/C\n",
+"printf('\nThe electric flux through the surface = %d N-Sq.m/C', phi_E);\n",
+"// Result \n",
+"// The electric flux through the surface = 800 N-Sq.m/C "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.32: Electric_flux_through_an_area_in_XY_plane.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex2.32: Page-93 (2008)\n",
+"clc; clear;\n",
+"E = [8 4 3];    // Coefficients of i, j and k in the electric field, N/C\n",
+"S = [0; 0; 100];    // Coefficients of i, j and k in the area vector, Sq. m\n",
+"phi_E = E*S;    // Electric flux through the surface, N-Sq.m/C\n",
+"printf('\nThe electric flux through the area in XY plane = %d N-Sq.m/C', phi_E);\n",
+"// Result \n",
+"// The electric flux through the area in XY plane = 300 N-Sq.m/C "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.33: Electric_flux_through_a_surface_in_YZ_plane.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex2.33: Page-93 (2008)\n",
+"clc; clear;\n",
+"E = [2 3 4];    // Coefficients of i, j and k in the electric field, N/C\n",
+"S = [10; 0; 0];    // Coefficients of i, j and k in the area vector, Sq. m\n",
+"phi_E = E*S;    // Electric flux through the surface, N-Sq.m/C\n",
+"printf('\nThe electric flux through the surface in YZ plane = %d N-Sq.m/C', phi_E);\n",
+"// Result \n",
+"// The electric flux through the surface in YZ plane = 20 N-Sq.m/C"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.39: Magnetic_field_due_to_a_straight_conductor_carrying_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex2.39: Page-96 (2008)\n",
+"clc; clear;\n",
+"mu_0 = 4*%pi*1e-007;    // Absolute magnetic permeability of free space, N/ampere-square\n",
+"I = 15;    // Current through the wire, A\n",
+"x = 1e-002;    // Distance of observation point from the wire, m\n",
+"B = mu_0/(4*%pi)*2*I/x;    // Magnetic field at 1 cm distance, T\n",
+"printf('\nThe magnetic field due to the current carrying wire at %d cm distance = %1.0e tesla', x/1e-002, B);\n",
+"x = 5;    // Distance of observation point from the infinite straight conductor, m\n",
+"I = 100;    // Current through the straight conductor, A\n",
+"B = mu_0/(4*%pi)*2*I/x;    // Magnetic field at 1 cm distance, T\n",
+"printf('\nThe magnetic field due to the current carrying infinite straight conductor at %d m distance = %1.0e tesla', x, B);\n",
+"// Result \n",
+"// The magnetic field due to the current carrying wire at 1 cm distance = 3e-004 tesla\n",
+"// The magnetic field due to the current carrying infinite straight conductor at 5 m distance = 4e-006 tesla "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.40: Force_between_two_current_carrying_straight_wires.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex2.40: Page-96 (2008)\n",
+"clc; clear;\n",
+"mu_0 = 4*%pi*1e-007;    // Absolute magnetic permeability of free space, N/ampere-square\n",
+"I1 = 30;    // Current through the first wire, A \n",
+"I2 = 40;    // Current through the second wire, A \n",
+"x = 2;    // Separation distance between two wires, m\n",
+"F = mu_0/(4*%pi)*2*I1*I2/x;    // Force between two current carrying straight wires, N\n",
+"printf('\nThe force between two current carrying straight wires = %3.1e N', F);\n",
+"// Result\n",
+"// The force between two current carrying straight wires = 1.2e-004 N "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Engineering_Physics_by_D_C_Ghosh/3-Vibration_Waves_and_Light.ipynb b/Engineering_Physics_by_D_C_Ghosh/3-Vibration_Waves_and_Light.ipynb
new file mode 100644
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--- /dev/null
+++ b/Engineering_Physics_by_D_C_Ghosh/3-Vibration_Waves_and_Light.ipynb
@@ -0,0 +1,1672 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 3: Vibration Waves and Light"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_02: Frequency_of_particle_executing_SHM.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.a.2: Page-132 (2008)\n",
+"clc; clear;\n",
+"m = 10;    // Mass of the particle, g\n",
+"x = poly(0, 'x');\n",
+"V = 50*x^2 + 100;    // Potential field surrounding the particle, erg/g\n",
+"U = m*V;    // Potential energy of the particle field system, erg\n",
+"F = -derivat(U);    // Force acting on the particle, dyne\n",
+"// As F = -m*a = -m*omega^2*x = -m*(2%pi*f)^2*x, solving for f\n",
+"f = sqrt(eval(pol2str(-pdiv(F,x)/m)))/(2*%pi);    // Frequency of oscillations of the particle executing SHM, Hz\n",
+"printf('\nThe frequency of oscillations of the particle executing SHM = %4.2f Hz', f);\n",
+"\n",
+"// Result\n",
+"// The frequency of oscillations of the particle executing SHM = 1.59 Hz "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_03: A_body_executing_SHM.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.a.3:Page-133 (2008)\n",
+"clc; clear;\n",
+"v1 = 80;    // Velocity of the body at 3 cm displacement, cm/s\n",
+"v2 = 60;    // Velocity of the body at 4 cm displacement, cm/s\n",
+"x1 = 3;    // Displacement of the body at velocity of 80 cm/s\n",
+"x2 = 4;    // Displacement of the body at velocity of 60 cm/s\n",
+"// As v = omega*sqrt(a^2 - x^2), solving for a\n",
+"a = poly(0, 'a');\n",
+"a = roots(v1^2*(a^2-16) - v2^2*(a^2 - 9));\n",
+"omega = v1/sqrt(a(1)^2 - x1^2);    // Angular ferquency of the oscillations, rad/s\n",
+"x = a(1);    // Maximum displacement, cm\n",
+"// As x = a*sin(omega*t), solving for t\n",
+"t_ex = asin(x/a(1))/omega;    // Time taken to reach the +ve extremity, s\n",
+"d = a(1) - 2.5;    // Distance of the point from the mean position, cm\n",
+"t = asin(d/a(1))/omega;    // Time taken to travel from mean position to positive extremity, s\n",
+"printf('\nThe time taken to travel from 2.5 cm from +ve extremity = %5.3f s', t_ex - t);    \n",
+"\n",
+"// Result\n",
+"// The time taken to travel from 2.5 cm from +ve extremity = 0.052 s "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_04: Time_period_of_a_body_oscillating_in_the_tunnel_across_the_earth.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.a.4: Page-134 (2008)\n",
+"clc; clear;\n",
+"R = 6.4e+006;    // Radius of the earth, m\n",
+"g = 10;    // Acceleration due to gravity, m/sec-square\n",
+"T = 2*%pi*sqrt(R/g);    // Time period of oscillations of the body, s\n",
+"printf('\nThe time period of oscillations of the body = %4.1f min', T/60);\n",
+"\n",
+"// Result\n",
+"// The time period of oscillations of the body = 83.8 min "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_05: Resultant_amplitude_and_phase_angle_relative_to_the_first_SHM.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.a.5: Page-135 (2008)\n",
+"clc; clear;\n",
+"phi1 = 0;    // Phase of the first SHM, degree\n",
+"phi2 = 60;    // Phase of the second SHM, degree\n",
+"phi3 = 90;    // Phase of the third SHM, degree\n",
+"a1 = 1.0;    // Amplitude of the first SHM, cm\n",
+"a2 = 1.5;    // Amplitude of the second SHM, cm\n",
+"a3 = 2.0;    // Amplitude of the third SHM, cm\n",
+"A = sqrt((a1 + a2*cosd(phi2)+a3*cosd(phi3))^2 + (a2*sind(phi2)+a3*sind(phi3))^2);    // Resultant amplitude relative to the first SHM, cm\n",
+"phi = atand((a2*sind(phi2)+a3*sind(phi3))/(a1 + a2*cosd(phi2)+a3*cosd(phi3)));    // Resultant phase angle relative to the first SHM, degree\n",
+"printf('\nThe resultant amplitude and phase angle relative to the first SHM = %4.2f cm and %2d degrees respectively', A, phi);\n",
+"\n",
+"// Result\n",
+"// The resultant amplitude and phase angle relative to the first SHM are 3.73 cm and 62 degrees respectively"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_07: Two_SHMs_acting_in_the_same_direction.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.a.7:Page-136 (2008)\n",
+"clc; clear;\n",
+"phi1 = 0;    // Phase of the first SHM, degree\n",
+"phi2 = 45;    // Phase of the second SHM, degree\n",
+"a1 = 0.005;    // Amplitude of the first SHM, m\n",
+"a2 = 0.002;    // Amplitude of the second SHM, m\n",
+"A = sqrt((a1 + a2*cosd(phi2))^2 + (a2*sind(phi2))^2);    // Resultant amplitude relative to the first SHM, m\n",
+"phi = atand(a2*sind(phi2)/(a1 + a2*cosd(phi2)));    // Resultant phase angle relative to the first SHM, degree\n",
+"printf('\nThe amplitude of the resultant displacement and phase angle relative to the first SHM are %7.5f m and %5.2f degrees respectively', A, phi);\n",
+"\n",
+"// Result\n",
+"// The amplitude of the resultant displacement and phase angle relative to the first SHM are 0.00657 m and 12.43 degrees respectively  "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_11: A_spring_disc_system_undergoing_damped_oscillation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.b.1: Page-138 (2008)\n",
+"clc; clear;\n",
+"m = 100;    // Mass of the horizontal disc, g\n",
+"t = 60;    // Time during which the amplitude reduces to half of its undamped value, s\n",
+"f = 10;    // Frequency of oscillations of the system, Hz\n",
+"omega_prime = 2*%pi*f;    // Angular frequency of the oscillations, rad/s\n",
+"A0 = 1;    // Assume the amplitude of undamped oscillations to be unity, cm\n",
+"// As A = A0*exp(-k*t), solving for k\n",
+"A = A0/2;    // Amplitude of damped oscillations after 1 min, cm\n",
+"k = log(A0/A)/t;    // Resisting force per unit mass per unit velocity, nepers/sec\n",
+"r = 2*k*m;    // Resistive force constant, sec/cm\n",
+"tau = 1/k;    // Relaxation time, sec\n",
+"Q = m*omega_prime/r;    // Quality factor\n",
+"s = m*(omega_prime^2 + k^2);    // Force constant of the spring, dynes/Sq.cm\n",
+"printf('\nThe resistive force constant = %4.2f dyne-sec/cm', r);\n",
+"printf('\nThe relaxation time of the system = %4.2f sec', tau);\n",
+"printf('\nThe quality factor, Q = %4.2f', Q);\n",
+"printf('\nThe force constant of the spring = %4.2e dyne/Sq.cm', s);\n",
+"\n",
+"// Result\n",
+"// The resistive force constant = 2.31 dyne-sec/cm\n",
+"// The relaxation time of the system = 86.56 sec\n",
+"// The quality factor, Q = 2719.42\n",
+"// The force constant of the spring = 3.95e+005 dyne/Sq.cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_12: A_mass_executing_damped_oscillations_in_one_dimension.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.b.2: Page-139 (2008)\n",
+"clc; clear;\n",
+"function m = check_motion_type(k, omega0)\n",
+"    if k > omega0 then\n",
+"        m = 'aperiodic';\n",
+"    else if  k == omega0 then\n",
+"            m = 'criticallydamped';\n",
+"        else if  k < omega0 then\n",
+"                m = 'oscillatory';\n",
+"            end\n",
+"        end\n",
+"    end\n",
+"endfunction\n",
+"m = 10;    // Mass of the body, g\n",
+"s = 10;    // Restoring force, dyne/cm\n",
+"r = 2;    // Resistive force constant, dyne.sec/cm\n",
+"k = r/(2*m);    // Resisting force, nepers/sec\n",
+"// As omega0^2 = s/m, solving for omega0\n",
+"omega0 = sqrt(s/m);    // Angular frequency, rad/s\n",
+"motion = check_motion_type(k, omega0);    // Check for the type of motion\n",
+"r_new = 2*sqrt(m*s);    // Resistive force constant, dyne-sec/cm\n",
+"m = r^2/(4*s);    // Mass for which the given forces makes the motion critically damped, g\n",
+"printf('\nThe motion is %s in nature', motion);\n",
+"printf('\nThe resistive force constant = %d dyne-sec/cm', r_new);\n",
+"printf('\nThe mass for which the given forces makes the motion critically damped = %3.1f g', m);\n",
+"\n",
+"// Result\n",
+"// The motion is oscillatory in nature\n",
+"// The resistive force constant = 20 dyne-sec/cm\n",
+"// The mass for which the given forces makes the motion critically damped = 0.1 g "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_14: A_mass_executing_damped_oscillations_in_one_dimension.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.b.4: Page-140 (2008)\n",
+"clc; clear;\n",
+"m = 1;    // Mass of the suspended body, kg\n",
+"s = 25;    // Stifness constant of the spring, N/m\n",
+"r = poly(0, 'r');\n",
+"// As f0/f_prime = 2/sqrt(3), solving for r\n",
+"r = roots(4*(s/m-r^2/(4*m^2))-3*s/m);    // Damping factor, kg/sec\n",
+"printf('\nThe damping factor of damped oscillations = %d kg/sec', r(1));\n",
+"\n",
+"// Result\n",
+"// The damping factor of damped oscillations = 5 kg/sec "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_15: Resisting_force_for_critically_damped_motion.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"// Scilab Code Ex3a.b.5: Page-141 (2008)\n",
+"clc; clear;\n",
+"function m = check_motion_type(k, omega0)\n",
+"    if k > omega0 then\n",
+"        m = 'aperiodic';\n",
+"    else if  k == omega0 then\n",
+"            m = 'criticallydamped';\n",
+"        else if  k < omega0 then\n",
+"                m = 'oscillatory';\n",
+"            end\n",
+"        end\n",
+"    end\n",
+"endfunction\n",
+"m = 10;    // Mass of the oscillating body, g\n",
+"r = 2;    // Resisting force, dyne-sec/cm\n",
+"s = 5;    // Restoring force, dyne/cm\n",
+"k = r/(2*m);    // Resisting force, nepers/sec\n",
+"// As omega0^2 = s/m, solving for omega0\n",
+"omega0 = sqrt(s/m);    // Angular frequency, rad/s\n",
+"motion = check_motion_type(k, omega0);    // Check for the type of motion\n",
+"r = 2*sqrt(m*s);    // Resistive force constant for critical damping, dyne-sec/cm\n",
+"printf('\nThe motion is %s in nature', motion);\n",
+"printf('\nThe resistive force constant for critical damping = %4.1f dyne-sec/cm', r);\n",
+"\n",
+"// Result\n",
+"// The motion is oscillatory in nature\n",
+"// The resistive force constant for critical damping = 14.1 dyne-sec/cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_16: Damped_oscillatory_motio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.b.6: Page-141 (2008)\n",
+"clc; clear;\n",
+"m = 0.1;    // Mass of the oscillating body, kg\n",
+"t = 50;    // Time during which the energy of system decays to 1/e of its undamped value, s\n",
+"s = 10;    // Spring constant, N/m\n",
+"E0 = 1;    // Assume the energy of undamped oscillations to be unity, erg\n",
+"// As E = E0*exp(-k*t) and E/E0 = 1/e,  solving for k\n",
+"E = E0/%e;    // Energy of damped oscillations after 50 sec, erg\n",
+"k = log(E0/E)/t;    // Resisting force per unit mass per unit velocity, nepers/sec\n",
+"p = m*k;    // A resistive force constant, N-s/m\n",
+"omega0 = sqrt(s/m);    // Angular frequency in the absence of damping, rad/sec\n",
+"omega_prime = sqrt(omega0^2 - k^2/4);    // Angular frequency when damping takes place, rad/sec\n",
+"Q = omega_prime/k;    // Quality factor\n",
+"printf('\nThe resistive force constant, p = %1.0e N-s/m', p);\n",
+"printf('\nThe quality factor, Q = %d', ceil(Q));\n",
+"\n",
+"// Result\n",
+"// The resistive force constant, p = 2e-003 N-s/m\n",
+"// The quality factor, Q = 500 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_17: Damped_simple_harmonic_motion.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.b.7: Page-142 (2008)\n",
+"clc; clear;\n",
+"t = 10;    // Time during which the amplitude reduces to 1/10th of its undamped value, s\n",
+"f = 200;    // Frequency of oscillations of the system, Hz\n",
+"omega0 = 2*%pi*f;    // Angular frequency of the oscillations, rad/s\n",
+"A0 = 1;    // Assume the amplitude of undamped oscillations to be unity, cm\n",
+"// As A = A0*exp(-k*t), solving for k\n",
+"A = A0/10;    // Amplitude of damped oscillations after 10 sec, cm\n",
+"k = log(A0/A)/t;    // Resisting force per unit mass per unit velocity, nepers/sec\n",
+"tau = 1/(2*k);    // Relaxation time, sec\n",
+"Q = omega0*tau;   // Quality factor\n",
+"E0 = 1;    // Assume energy of undamped oscillations to be unity, erg\n",
+"E = E0/10;    // Energy of damped oscillations after t sec, erg\n",
+"// As E = E0*exp(-2*k*t), solving for t\n",
+"t = 1/(2*k)*log(E0/E);    // Time during which the energy falls to 1/10 of its initial value, sec\n",
+"printf('\nThe relaxation time = %4.2f sec', tau);\n",
+"printf('\nThe quality factor, Q = %d', Q);\n",
+"printf('\nThe time during which the energy falls to 1/10 of its initial value = %d sec', t);\n",
+"printf('\nThe damping constant, k = %4.2f', k);\n",
+"\n",
+"// Result\n",
+"// The relaxation time = 2.17 sec\n",
+"// The quality factor, Q = 2728\n",
+"// The time during which the energy falls to 1/10 of its initial value = 5 sec\n",
+"// The damping constant, k = 0.23 \n",
+"// The answer for Q is given wrongly in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_21: Characteristics_of_progressive_waves.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.c.1: Page-143 (2008)\n",
+"clc; clear;\n",
+"// Comparing with the standard progressive wave equation, we have\n",
+"a = 0.5;    // Amplitude of the wave, m\n",
+"lambda = 2*%pi/12.56;    // Wavelength of the wave, m\n",
+"v = 314/12.56;    // Wave velocity, m/s\n",
+"nu = v/lambda;    // Frequency of the wave, Hz\n",
+"printf('\nThe amplitude of the wave = %3.1f m', a);\n",
+"printf('\nThe wavelength of the wave = %3.1f m', lambda);\n",
+"printf('\nThe velocity of the wave = %d m/s', v);\n",
+"printf('\nThe frequency of the wave = %d Hz', ceil(nu));\n",
+"\n",
+"// Result\n",
+"// The amplitude of the wave = 0.5 m\n",
+"// The wavelength of the wave = 0.5 m\n",
+"// The velocity of the wave = 25 m/s\n",
+"// The frequency of the wave = 50 Hz "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_22: A_simple_harmonic_wave_travelling_along_X_axis.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.c.2: Page-144 (2008)\n",
+"clc; clear;\n",
+"// Comparing with the standard progressive wave equation, we have\n",
+"a = 5;    // Amplitude of the wave, m\n",
+"nu = 0.2;    // Frequency of the wave, Hz\n",
+"lambda = 1/0.5;    // Wavelength of the wave, m\n",
+"v = nu*lambda;    // Wave velocity, m/s\n",
+"printf('\nThe amplitude of the wave = %3.1f m', a);\n",
+"printf('\nThe wavelength of the wave = %3.1f m', lambda);\n",
+"printf('\nThe velocity of the wave = %3.1f m/s', v);\n",
+"printf('\nThe frequency of the wave = %3.1f Hz', nu);\n",
+"\n",
+"// Result\n",
+"// The amplitude of the wave = 5.0 m\n",
+"// The wavelength of the wave = 2.0 m\n",
+"// The velocity of the wave = 0.4 m/s\n",
+"// The frequency of the wave = 0.2 Hz   "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.a_23: Travelling_wave_characteristics_and_phase_difference.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3a.c.3: Page-144 (2008)\n",
+"clc; clear;\n",
+"// Comparing with the standard progressive wave equation, we have\n",
+"a = 8;    // Amplitude of the wave, cm\n",
+"nu = 4/2;    // Frequency of the wave, Hz\n",
+"lambda = 2/0.02;    // Wavelength of the wave, cm\n",
+"v = nu*lambda;    // Wave velocity, cm/s\n",
+"delta_x = 20;    // Path difference between two particles, cm\n",
+"delta_phi = delta_x*2*%pi/lambda*180/%pi;    // Phase difference between two particles, degree\n",
+"printf('\nThe amplitude of the wave = %3.1f cm', a);\n",
+"printf('\nThe wavelength of the wave = %3.1f cm', lambda);\n",
+"printf('\nThe velocity of the wave = %3.1f cm/s', v);\n",
+"printf('\nThe frequency of the wave = %d Hz', nu);\n",
+"printf('\nThe phase difference between two particles = %d degree', delta_phi);\n",
+"\n",
+"// Result\n",
+"// The amplitude of the wave = 8.0 cm\n",
+"// The wavelength of the wave = 100.0 cm\n",
+"// The velocity of the wave = 200.0 cm/s\n",
+"// The frequency of the wave = 2 Hz\n",
+"// The phase difference between two particles = 72 degree "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.b_101: Brewster_angle_and_angle_of_refraction_for_glass.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3b.1: Page-163 (2008)\n",
+"clc; clear;\n",
+"mu = 1.5;    // Refractive indexof glass\n",
+"i_p = atand(mu);    // Angle of polarization from Brewster's law, degree\n",
+"r = 90 - i_p;    // Angale of refraction, degree\n",
+"printf('\nThe Brewster angle for glass = %4.1f degree', i_p);\n",
+"printf('\nThe angle of refraction for glass = %4.1f degree', r);\n",
+"\n",
+"// Result\n",
+"// The Brewster angle for glass = 56.3 degree\n",
+"// The angle of refraction for glass = 33.7 degree "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.b_102: Polarizing_angles_for_various_pair_of_media.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3b.2: Page-163 (2008)\n",
+"clc; clear;\n",
+"// Function to convert degree to degree-minute\n",
+"function [d,m]= deg2deg_min(deg)\n",
+"    d = int(deg);\n",
+"    m = (deg - d)*60;\n",
+"endfunction\n",
+"mu_air = 1;    // Refractive index fo air\n",
+"mu_glass = 1.54;    // Refractive index of glass\n",
+"mu_water = 1.33;    // Refractive index of water\n",
+"// Air to glass incidence\n",
+"i_p = atand(mu_glass/mu_air);    // Angle of polarization for air to glass incidence, degree\n",
+"printf('\nFor air to glass, i_p = %d degree', i_p);\n",
+"// glass to air incidence\n",
+"i_p = atand(mu_air/mu_glass);    // Angle of polarization for glass to air incidence, degree\n",
+"printf('\nFor glass to air, i_p = %d degree', ceil(i_p));\n",
+"// Water to glass incidence\n",
+"i_p = atand(mu_glass/mu_water);    // Angle of polarization for water to glass incidence, degree\n",
+"[d,m] = deg2deg_min(i_p);    // Call function to convert to deg-min\n",
+"printf('\nFor water to glass, i_p = %d degree %d min', d, m);\n",
+"// Glass to water incidence\n",
+"i_p = atand(mu_water/mu_glass);    // Angle of polarization for glass to water incidence, degree\n",
+"[d,m] = deg2deg_min(i_p);    // Call function to convert to deg-min\n",
+"printf('\nFor glass to water, i_p = %d degree %d min', d, m);\n",
+"// Air to water incidence\n",
+"i_p = atand(mu_water/mu_air);    // Angle of polarization for air to water incidence, degree\n",
+"[d,m] = deg2deg_min(i_p);    // Call function to convert to deg-min\n",
+"printf('\nFor air to water, i_p = %d degree %d min', d, m);\n",
+"// Water to air incidence\n",
+"i_p = atand(mu_air/mu_water);    // Angle of polarization for water to airincidence, degree\n",
+"[d,m] = deg2deg_min(i_p);    // Call function to convert to deg-min\n",
+"printf('\nFor water to air, i_p = %d degree %d min', d, m);\n",
+"\n",
+"// Result\n",
+"// For air to glass, i_p = 57 degree\n",
+"// For glass to air, i_p = 33 degree\n",
+"// For water to glass, i_p = 49 degree 11 min\n",
+"// For glass to water, i_p = 40 degree 48 min\n",
+"// For air to water, i_p = 53 degree 3 min\n",
+"// For water to air, i_p = 36 degree 56 min "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.b_103: Polarizing_angle_for_glass.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3b.3: Page-163 (2008)\n",
+"clc; clear;\n",
+"C = 40;    // Critical angle for glass to air\n",
+"mu = 1/sind(C);    // Refractive index of glass w.r.t. air\n",
+"i_p = atand(mu);    // Polarizing angle for glass, degree\n",
+"printf('\nThe polarizing angle for glass = %4.1f degree', i_p);\n",
+"\n",
+"// Result\n",
+"// The polarizing angle for glass = 57.3 degree "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.b_104: Polarization_by_reflection.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3b.4: Page-164 (2008)\n",
+"clc; clear;\n",
+"i = 60;    // Angle of incidence, degree\n",
+"i_p = i;    // Angle of polarization, degree\n",
+"mu = tand(i_p);    // Refractive index of the medium\n",
+"r = 90 - i;    // Angle of refraction, degree\n",
+"printf('\nThe refractive index of transparent medium = %5.3f', mu);\n",
+"printf('\nThe angle of refraction, r = %d degree', r);\n",
+"printf('\nThe reflected and transmitted components are at right angles to each other.');\n",
+"\n",
+"// Result\n",
+"// The refractive index of transparent medium = 1.732\n",
+"// The angle of refraction, r = 30 degree\n",
+"// The reflected and transmitted components are at right angles to each other."
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.b_105: Intensity_ratio_of_two_beams_through_analyser.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3b.5: Page-164 (2008)\n",
+"clc; clear;\n",
+"theta_A = 30;    // Angle between principal sections of polariser and  analyser for beam A, degree\n",
+"theta_B = 60;    // Angle between principal sections of polariser and  analyser for beam B, degree\n",
+"// As I_A*cosd(theta_A)^2 = I_B*cosd(theta_B)^2, solving for I ratio\n",
+"I_ratio = cosd(theta_B)^2/cosd(theta_A)^2;    // The intensity ratio of the two beams\n",
+"printf('\nThe intensity ratio of the two beams = %4.2f', I_ratio);\n",
+"\n",
+"// Result\n",
+"// The intensity ratio of the two beams = 0.33"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.b_106: Percentage_reduction_in_the_intensity_of_the_inident_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3b.6: Page-165 (2008)\n",
+"clc; clear;\n",
+"theta = [30 45 60 90];    // Angles between principal sections of polariser and analyser, degree\n",
+"for i = 1:1:4\n",
+"    P_red = (1-cosd(theta(i))^2)*100;    // Percentage reduction in intensity of incident light\n",
+"    printf('\nFor theta = %d degree, percentage reduction = %1.0f percent', theta(i), P_red);\n",
+"end\n",
+"\n",
+"// Result\n",
+"// For theta = 30 degree, percentage reduction = 25 percent\n",
+"// For theta = 45 degree, percentage reduction = 50 percent\n",
+"// For theta = 60 degree, percentage reduction = 75 percent\n",
+"// For theta = 90 degree, percentage reduction = 100 percent "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.b_107: Angle_of_rotation_of_polaroid_to_reduce_the_intensity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3b.7: Page-165 (2008)\n",
+"clc; clear;\n",
+"// For half reduction in intensity\n",
+"I_ratio = 1/2;    // Intensity ratio\n",
+"theta = acosd(sqrt(I_ratio));    // Angle of rotation of polaroid, degree\n",
+"printf('\nFor half reduction in intensity, the angle of rotation = %d degree', theta);\n",
+"// For one-fourth reduction in intensity\n",
+"I_ratio = 1/4;    // Intensity ratio\n",
+"theta = acosd(sqrt(I_ratio));    // Angle of rotation of polaroid, degree\n",
+"printf('\nFor one-fourth reduction in intensity, the angle of rotation = %d degree', theta);\n",
+"\n",
+"// Result\n",
+"// For half reduction in intensity, the angle of rotation = 45 degree\n",
+"// For one-fourth reduction in intensity, the angle of rotation = 60 degree "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_202: Ratio_of_maximum_to_minimum_intensity_in_the_interference_fringe_system.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.2: Page-184 (2008)\n",
+"clc; clear;\n",
+"I2 = 1;    // Assume intensity of light beam from the second source to be unity\n",
+"I1 = 81*I2;    // Intensity of light beam from the first source\n",
+"a = sqrt(I1);    // Width of the first slit, mm\n",
+"b = sqrt(I2);    // Width of the second slit, mm\n",
+"I_max = (1+a/b)^2;    // Maximum intensity in the fringe pattern\n",
+"I_min = (1-a/b)^2;    // Minimum intensity in the fringe pattern\n",
+"fact = gcd([I_max,I_min]); // Find l.c.m. of I_max and I_min\n",
+"printf('\nThe ratio of maximum to minimum intensity in the fringe system, I_max:I_min = %d:%d', I_max/4, I_min/4);\n",
+"\n",
+"// Result\n",
+"// The ratio of maximum to minimum intensity in the fringe system, I_max:I_min = 25:16 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_203: Wavelength_of_light_from_interference_of_fringes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.3: Page-184 (2008)\n",
+"clc; clear;\n",
+"d = 0.1;    // Separation between the two slits, cm\n",
+"D = 100;    // Distance between the source and the slit, cm\n",
+"bita = 0.05;    // Fringe width, cm\n",
+"lambda = bita*d/D;    // Wavelength of light, cm\n",
+"printf('\nThe wavelength of light used = %4d angstrom', lambda/1e-008);\n",
+"\n",
+"// Result\n",
+"// The wavelength of light used = 5000 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_204: Fringe_width_from_interference_pattern.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.4: Page-184 (2008)\n",
+"clc; clear;\n",
+"d = 0.3;    // Separation between the two slits, cm\n",
+"D = 60;    // Distance between the source and the slit, cm\n",
+"lambda = 59e-006;    // Wavelength of light, cm\n",
+"bita = lambda*D/d;    // Fringe width, cm\n",
+"printf('\nThe fringe width = %4.2e cm', bita);\n",
+"\n",
+"// Result\n",
+"// The fringe width = 1.18e-002 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_205: Distance_between_the_two_coherent_sources.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.5: Page-185 (2008)\n",
+"clc; clear;\n",
+"D = 80;    // Distance between the source and the slit, cm\n",
+"lambda = 5890e-008;    // Wavelength of light, cm\n",
+"bita = 9.424e-002;    // Fringe width, cm\n",
+"d = lambda*D/bita;    // Separation between the two slits, cm\n",
+"printf('\nThe distance between the two coherent sources = %4.2f cm', d);\n",
+"\n",
+"// Result\n",
+"// The distance between the two coherent sources = 0.05 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_206: Distance_between_consecutive_interference_bands.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.6: Page-185 (2008)\n",
+"clc; clear;\n",
+"D = 100;    // Distance between the source and the slit, cm\n",
+"lambda = 5893e-008;    // Wavelength of light, cm\n",
+"d1 = 4.05e-001;    // Distance between the images of the two slits in one position, cm\n",
+"d2 = 2.90e-001;    // Distance between the images of the two slits in second position, cm\n",
+"d = sqrt(d1*d2);   // Separation between the two slits, cm\n",
+"bita = lambda*D/d;    // Fringe width, cm\n",
+"printf('\nThe distance between consecutive interference bands = %6.4f cm', bita);\n",
+"\n",
+"// Result\n",
+"// The distance between consecutive interference bands = 0.0172 cm"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_207: Wavelength_of_the_light_used_in_biprism_experiment.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.7: Page-185 (2008)\n",
+"clc; clear;\n",
+"D = 1.2;    // Distance between the source and the slit, m\n",
+"d = 7.5e-004;   // Separation between the two slits, cm\n",
+"n = 20;    // Number of fringes crossed in the field of view\n",
+"bita = 1.888e-002/n;    // Fringe width, cm\n",
+"lambda = bita*d/D;    // Wavelength of light, cm\n",
+"printf('\nThe wavelength of the light used in biprism experiment = %4d angstrom', lambda/1e-010);\n",
+"\n",
+"// Result\n",
+"// The wavelength of the light used in biprism experiment = 5900 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_208: Number_of_fringes_obtained_with_the_given_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.8: Page-186 (2008)\n",
+"clc; clear;\n",
+"lambda1 = 5893;    // First wavelength of light, angstrom\n",
+"lambda2 = 4358;    // Second wavelength of light, angstrom\n",
+"n = 40;    // Number of fringes obtained with first wavelength\n",
+"// As bita1/bita2 = lambda1/lambda2, so\n",
+"x = n*lambda1/lambda2;    // Number of fringes obtained with the seocond wavelength\n",
+"printf('\nThe number of fringes obtained with the given wavelength = %d', x);\n",
+"\n",
+"// Result\n",
+"// The number of fringes obtained with the given wavelength = 54 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_209: Wavelength_of_light_from_biprism_interference_pattern.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.9: Page-186 (2008)\n",
+"clc; clear;\n",
+"D = 100;    // Distance between the source and the slit, cm\n",
+"bita = 0.0135;    // Fringe width, cm\n",
+"alpha = %pi/360;    // Angle of refracting face with the base of biprism, radian\n",
+"mu = 1.5;    // Refractive index of the material of biprism\n",
+"x = 50;    // Distance between slit and the biprism, cm\n",
+"d = 2*(mu-1)*x*alpha;   // Separation between the two virtual slits, cm\n",
+"lambda = bita*d/D;    // Wavelength of light, cm\n",
+"printf('\nThe wavelength of light from biprism interference pattern = %4d angstrom', lambda/1e-008);\n",
+"\n",
+"// Result\n",
+"// The wavelength of light from biprism interference pattern = 5890 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_210: Fringe_width_observed_at_one_metre_distance_from_biprism.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.10: Page-187 (2008)\n",
+"clc; clear;\n",
+"mu = 1.5;    // Refractive index of the material of biprism\n",
+"alpha = %pi/180;    // Base angle of biprism, radian\n",
+"D = 110;    // Distance between the source and the slit, cm\n",
+"x = 10;    // Distance between slit and the biprism, cm\n",
+"d = 2*(mu-1)*x*alpha;   // Separation between the two virtual slits, cm\n",
+"lambda = 5900e-008;    // Wavelength of light, cm\n",
+"bita = lambda*D/d;    // Fringe width, cm\n",
+"printf('\nThe fringe width observed at one metre distance from biprism = %6.4f cm', bita);\n",
+"\n",
+"// Result\n",
+"// The fringe width observed at one metre distance from biprism = 0.0372 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_211: Wavelength_of_light_in_Newton_ring_experiment.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.11: Page-187 (2008)\n",
+"clc; clear;\n",
+"D_n = 0.42;    // Diameter of nth ring, cm\n",
+"D_mplusn = 0.7;    // Diameter of (m+n)th ring, cm\n",
+"m = 14;    // Difference between (m+n)th and nth rings\n",
+"R = 100;    // Radius of curvature of the plano-convex lens, m\n",
+"lambda = (D_mplusn^2 - D_n^2)/(4*m*R);    // Wavelength of the light, cm\n",
+"printf('\nThe wavelength of the light used = %4d angstrom', lambda/1e-008);\n",
+"\n",
+"// Result\n",
+"// The wavelength of the light used = 5600 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_212: Radius_of_plano_convex_lens.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.12: Page-187 (2008)\n",
+"clc; clear;\n",
+"D5 = 0.336;    // Diameter of 5th ring, cm\n",
+"D10plus5 = 0.590;    // Diameter of (10+5)th ring, cm\n",
+"m = 10;    // Difference between (10+5)th and 5th rings\n",
+"lambda = 5890e-008;    // Wavelength of the light, cm\n",
+"R = (D10plus5^2 - D5^2)/(4*m*lambda);    // Radius of curvature of the plano-convex lens, m\n",
+"printf('\nThe radius of plano convex lens = %5.2f cm', R);\n",
+"\n",
+"// Result\n",
+"// The radius of plano convex lens = 99.83 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_213: Wavelenght_of_light_used_in_obtaining_Newton_rings.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.13: Page-187 (2008)\n",
+"clc; clear;\n",
+"D3 = 0.181;    // Diameter of 3rd ring, cm\n",
+"D23 = 0.501;    // Diameter of 23rd ring, cm\n",
+"m = 23-3;    // Difference between (m+n)th and nth rings\n",
+"R = 50;    // Radius of curvature of the plano-convex lens, m\n",
+"lambda = (D23^2 - D3^2)/(4*m*R);    // Wavelength of the light, cm\n",
+"printf('\nThe wavelength of the light used = %4d angstrom', lambda/1e-008);\n",
+"\n",
+"// Result\n",
+"// The wavelength of the light used = 5456 angstrom"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_214: Diameter_of_the_20th_dark_ring.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.14: Page-188 (2008)\n",
+"clc; clear;\n",
+"D4 = 0.4;    // Diameter of 4th ring, cm\n",
+"D12 = 0.7;    // Diameter of 12th ring, cm\n",
+"m = 12-4;    // Difference between (m+n)th and nth rings\n",
+"lambda_R = (D12^2 - D4^2)/(4*m);    // Wavelength-Radius product, Sq.cm\n",
+"D20 = sqrt(80*lambda_R);    // Diameter of the 20th dark ring, cm\n",
+"printf('\nThe diameter of the 20th dark ring = %5.3f cm', D20);\n",
+"\n",
+"// Result\n",
+"// The diameter of the 20th dark ring = 0.908 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_215: Radius_of_curvature_of_the_lens_and_the_thickness_of_the_air_film.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.15: Page-188 (2008)\n",
+"clc; clear;\n",
+"D10 = 0.50;    // Diameter of 10th ring, cm\n",
+"n = 10;    // Number of dark fringe\n",
+"lambda = 6250e-008;    // Wavelength of light used, cm\n",
+"R = D10^2/(4*n*lambda);    // Radius of curvature of the lens, cm\n",
+"t = D10^2/(8*R);    // Thickness of the air film, cm\n",
+"printf('\nThe radius of curvature of the lens = %3d cm', R);\n",
+"printf('\nThe thickness of the air film = %9.7f cm', t);\n",
+"\n",
+"// Result\n",
+"// The radius of curvature of the lens = 100 cm\n",
+"// The thickness of the air film = 0.0003125 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_216: Newton_rings_observed_in_reflected_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.16: Page-188 (2008)\n",
+"clc; clear;\n",
+"D10 = 5e-003;    // Diameter of 10th ring, cm\n",
+"n = 10;    // Number of dark fringe\n",
+"lambda = 5.9e-007;    // Wavelength of reflected light, m\n",
+"R = D10^2/(4*n*lambda);    // Radius of curvature of the lens, cm\n",
+"t = D10^2/(8*R);    // Thickness of the air film, cm\n",
+"printf('\nThe radius of curvature of the lens = %5.3f m', R);\n",
+"printf('\nThe thickness of the air film = %4.2e m', t);\n",
+"\n",
+"// Result\n",
+"// The radius of curvature of the lens = 1.059 m\n",
+"// The thickness of the air film = 2.95e-006 m  "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.c_217: Smallest_thickness_of_the_glass_film_in_which_it_appears_dark.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3c.17: Page-189 (2008)\n",
+"clc; clear;\n",
+"lambda = 5893e-010;    // Wavelength of light used, m\n",
+"mu = 1.5;    // Refractive index of glass film\n",
+"r = 60;    // Angle of reflection in the film, degree\n",
+"t = lambda/(2*mu*cosd(r));    // Smallest thickness of the \n",
+"printf('\nThe smallest thickness of the glass film when it appears dark = %6.1f angstrom', t/1e-010);\n",
+"\n",
+"// Result\n",
+"// The smallest thickness of the glass film when it appears dark = 3928.7 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_301: Wavelength_of_light_used_in_diffraction_due_to_narrow_slit.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.1: Page-205 (2008)\n",
+"clc; clear;\n",
+"D = 200;    // Distance between the source and the slit, cm\n",
+"a = 0.02;    // Slit width, cm\n",
+"x = 0.5;    // Position of first minimum, cm\n",
+"n = 1;    // Order of diffraction\n",
+"lambda = a*x/(D*n);    // Wavelength of light used, cm\n",
+"printf('\nThe wavelength of light used = %4d angstrom', lambda/1e-008);\n",
+"\n",
+"// Result\n",
+"// The wavelength of light used = 5000 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_302: Separation_between_the_second_minima_on_either_side_of_the_central_maximum.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.2: Page-205 (2008)\n",
+"clc; clear;\n",
+"f = 20;    // Focal length of the lens, cm\n",
+"a = 0.06;    // Slit width, cm\n",
+"n = 2;    // Order of diffraction\n",
+"lambda = 6e-005;    // Wavelength of light used, cm\n",
+"x = 2*lambda*f/a;    // Separation between the second minima on either side of the central maximum, cm\n",
+"printf('\nThe separation between the second minimum an central maximum = %4.2f cm', x);\n",
+"\n",
+"// Result\n",
+"// The separation between the second minimum an central maximum = 0.04 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_303: Distance_of_the_first_dark_band_from_the_axis.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.3: Page-206 (2008)\n",
+"clc; clear;\n",
+"n = 1;    // Order of diffraction\n",
+"f = 40;    // Focal length of the lens, cm\n",
+"a = 0.03;    // Slit width, cm\n",
+"lambda = 5890e-008;    // Wavelength of the light used, cm\n",
+"// As a*sind(theta) = n*lambda, solving for theta\n",
+"theta = asin(n*lambda/a);    // The angle of diffraction corresponding to the first minimum, radian\n",
+"x = f*theta;    // The distance of the first dark band from the axis, cm  \n",
+"printf('\nThe distance of the first dark band from the axis = %6.4f cm', x);\n",
+"\n",
+"// Result\n",
+"// The distance of the first dark band from the axis = 0.0785 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_304: Angle_of_diffraction_for_the_principal_maxima.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.4: Page-206 (2008)\n",
+"clc; clear;\n",
+"lambda1 = 5890e-008;    // Wavelength of D1 line of sodium lamp, cm\n",
+"lambda2 = 5896e-008;    // Wavelength of D2 line of sodium lamp, cm\n",
+"d_lambda = lambda2 - lambda1;    // Wavelength difference, cm\n",
+"w = 0.5;    // Width of the grating, cm\n",
+"N = 2500;    // Total number of grating lines\n",
+"N_prime = N/w;    // Number of lines per cm, lines/cm\n",
+"a_plus_b = 1/N_prime;    // Grating element, cm\n",
+"n = 1;    // Order of diffraction\n",
+"// Case 1\n",
+"theta = asind(n*lambda1/a_plus_b);    // Angle of diffraction for D1 line, degree\n",
+"// Case 2\n",
+"theta_prime = asind(n*lambda2/a_plus_b);    // Angle of diffraction for D2 line, degree\n",
+"printf('\nThe angle of diffraction for D1 and D2 lines of sodium are %5.2f dgree and %5.2f degree respectively.', theta, theta_prime);\n",
+"// From the condition for just resolution, lambda/d_lambda = n*N, solving for N\n",
+"N_min = lambda1/(d_lambda*n);    // Minimum number of lines required on the grating\n",
+"if N_min < N then\n",
+"    printf('\nThe two lines are well resolved.');\n",
+"else\n",
+"    printf('\nThe two lines are not resolved.');\n",
+"end\n",
+"\n",
+"// Result\n",
+"// The angle of diffraction for D1 and D2 lines of sodium are 17.13 dgree and 17.15 degree respectively.\n",
+"// The two lines are well resolved. "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_305: Wavelength_of_the_spectral_line.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.5: Page-207 (2008)\n",
+"clc; clear;\n",
+"N = 4250;    // Number of lines per cm of grating, lines/cm\n",
+"a_plus_b = 1/N;    // Grating element, cm\n",
+"n = 2;    // Order of diffraction\n",
+"theta = 30;    // Angle of diffraction, degree\n",
+"lambda = sind(theta)*a_plus_b/n;    // Wavelength of spectral line from diffraction condition, cm\n",
+"printf('\nThe wavelength of spectral line from diffraction condition = %4d angstrom', lambda/1e-008);\n",
+"\n",
+"// Result\n",
+"// The wavelength of spectral line from diffraction condition = 5882 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_306: Number_of_lines_in_one_centimeter_of_the_grating_surface.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.6: Page-207 (2008)\n",
+"clc; clear;\n",
+"n = 2;    // Order of diffraction\n",
+"lambda = 5e-005;    // Wavelength of light, cm\n",
+"theta = 30;    // Angle of diffraction, degree\n",
+"N = sind(theta)/(n*lambda);    // Number of lines per cm of grating, lines/cm\n",
+"printf('\nThe number of lines per cm of grating = %4d per cm', ceil(N));\n",
+"\n",
+"// Result\n",
+"// The number of lines per cm of grating = 5000 per cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_307: Highest_order_spectrum_obtainable_with_the_given_diffraction_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.7: Page-208 (2008)\n",
+"clc; clear;\n",
+"N = 5000;    // Number of lines per cm ruled on grating, lines/cm\n",
+"lambda = 6e-005;    // Wavelength of light, m\n",
+"a_plus_b = 1/N;    // Grating element, m\n",
+"theta = 90;    // Maximum angle of diffraction, degree\n",
+"n = a_plus_b*sind(theta)/lambda;    // Order of diffraction\n",
+"printf('\nIn highest order spectrum obtainable with the given diffraction grating = %4.2f', n);\n",
+"\n",
+"// Result\n",
+"// In highest order spectrum obtainable with the given diffraction grating = 3.33 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_308: Invisible_third_and_higher_order_principal_maxima_in_a_diffraction_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.8: Page-208 (2008)\n",
+"clc; clear;\n",
+"lambda = 5.5e-007;    // Wavelength of light, m\n",
+"a_plus_b = 1.5e-006;    // Grating element, m\n",
+"theta = 90;    // Maximum angle of diffraction, degree\n",
+"n = a_plus_b*sind(theta)/lambda;    // Order of diffraction\n",
+"printf('\nIn this diffraction grating only %dnd order will be visible while %drd and higher orders are not possible.', n, n+1);\n",
+"\n",
+"// Result\n",
+"// In this diffraction grating only 2nd order will be visible while 3rd and higher orders are not possible. "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_309: Number_of_lines_per_cm_on_the_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.9: Page-208 (2008)\n",
+"clc; clear;\n",
+"theta = 30;    // Maximum angle of diffraction, degree\n",
+"lambda1 = 5400e-010;    // Wavelength of light giving certain diffraction order, m\n",
+"lambda2 = 4050e-010;    // Wavelength of light giving higher diffraction order, m\n",
+"n = poly(0, 'n');\n",
+"n = roots(lambda1*n-(n+1)*lambda2);    // Order of diffraction for first wavelength\n",
+"a_plus_b = n*lambda1/sind(theta);    // Grating element, m\n",
+"N = 1/a_plus_b;    // Number of lines per cm ruled on grating, lines/cm\n",
+"printf('\nThe number of lines per cm on the diffraction grating = %d lines per cm', N/100);\n",
+"\n",
+"// Result\n",
+"// The number of lines per cm on the diffraction grating = 3086 lines per cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_310: Minimum_number_of_lines_on_the_diffraction_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.10: Page-209 (2008)\n",
+"clc; clear;\n",
+"lambda = 5890e-008;    // Wavelength of light, cm\n",
+"n = 1;    // Order of diffraction\n",
+"d_lambda = 6e-008;    // Difference in wavelengths of D1 and D2 lines, cm\n",
+"N = lambda/(n*d_lambda);    // Number of lines on grating\n",
+"printf('\nThe minimum number of lines on the diffraction grating = %d', ceil(N));\n",
+"\n",
+"// Result\n",
+"// The minimum number of lines on the diffraction grating = 982 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_311: Design_of_a_plane_transmission_diffraction_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.11: Page-209 (2008)\n",
+"clc; clear;\n",
+"lambda = 6000e-008;    // Wavelength of light, cm\n",
+"n = 2;    // Order of diffraction\n",
+"d_lambda = 6e-008;    // Difference in wavelengths of D1 and D2 lines, cm\n",
+"N = lambda/(n*d_lambda);    // Number of lines on grating\n",
+"printf('\nThe minimum number of lines in the required diffraction grating = %d', N);\n",
+"\n",
+"// Result\n",
+"// The minimum number of lines in the required diffraction grating = 500 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_312: EX3_d_312.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.12: Page-209 (2008)\n",
+"clc; clear;\n",
+"lambda = 5890e-008;    // Wavelength of light, cm\n",
+"n = 2;    // Order of diffraction\n",
+"d_lambda = 6e-008;    // Difference in wavelengths of D1 and D2 lines, cm\n",
+"w = 2.5;    // Width of the grating, cm\n",
+"N = lambda/(n*d_lambda);    // Number of lines on grating\n",
+"printf('\nThe minimum number of lines per cm in the diffraction grating = %5.1f', N/w);\n",
+"\n",
+"// Result\n",
+"// The minimum number of lines per cm in the diffraction grating = 196.3 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_313: Maximum_resolving_power_of_a_plane_transmission_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.13: Page-210 (2008)\n",
+"clc; clear;\n",
+"lambda = 5000e-008;    // Wavelength of light, cm\n",
+"theta = 90;    // Angle of diffraction for the maximum resolving power, degree\n",
+"N = 40000;    // Number of lines on grating\n",
+"a_plus_b = 12.5e-005;    // Grating element, cm\n",
+"n = 2;    // Order of diffraction\n",
+"n_max = N*a_plus_b*sind(theta)/lambda;    // Maximum resolving power\n",
+"printf('\nThe maximum resolving power = %d', n_max);\n",
+"\n",
+"// Result\n",
+"// The maximum resolving power = 100000 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.d_314: Maximum_number_of_lines_of_a_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3d.14: Page-209 (2008)\n",
+"clc; clear;\n",
+"lambda = 5890e-008;    // Wavelength of light, cm\n",
+"n = 3;    // Order of diffraction\n",
+"d_lambda = 6e-008;    // Difference in wavelengths of D1 and D2 lines, cm\n",
+"N = lambda/(n*d_lambda);    // Maximum number of lines of a grating\n",
+"printf('\nThe maximum number of lines of the grating = %d', N);\n",
+"\n",
+"// Result\n",
+"// The maximum number of lines of the grating = 327 "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Engineering_Physics_by_D_C_Ghosh/4-Special_Theory_of_Relativity.ipynb b/Engineering_Physics_by_D_C_Ghosh/4-Special_Theory_of_Relativity.ipynb
new file mode 100644
index 0000000..30894df
--- /dev/null
+++ b/Engineering_Physics_by_D_C_Ghosh/4-Special_Theory_of_Relativity.ipynb
@@ -0,0 +1,372 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 4: Special Theory of Relativity"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.10: Relativisti_variation_of_mass_of_electron_with_velocity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.10: Page-238 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"m0 = 9.1e-031;    // Rest mass of the electron, kg\n",
+"E0 = m0*c^2;    // Rest energy of the electron, J\n",
+"printf('\nThe rest energy of the electron = %4.2f MeV', E0/1.6e-013);\n",
+"E = 1.25*E0;    // Total energy of the particle\n",
+"v = sqrt(1-(E0/E)^2)*c;    // Velocity of the particle from relativistic variation of mass with speed, m/s\n",
+"printf('\nThe velocity of the electron when its total energy is 1.25 times its rest energy = %3.1f c = %3.1e cm/s', v/c, v);\n",
+"\n",
+"// Result\n",
+"// The rest energy of the electron = 0.51 MeV\n",
+"// The velocity of the electron when its total energy is 1.25 times its rest energy = 0.6 c = 1.8e+008 cm/s"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.11: An_electron_subjected_to_relativistic_motion.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.11: Page-238 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"v = 0.99*c;    // Speed of the electron, m/s\n",
+"m0 = 9.1e-031;    // Rest mass of the electron, kg\n",
+"m = m0/sqrt(1-v^2/c^2);    // Moving mass of the electron, kg\n",
+"E = m*c^2;    // Total energy of the electron, J\n",
+"printf('\nThe total energy of the electron = %4.2e J', E);\n",
+"KE_ratio = m0/(2*(m-m0))*(v/c)^2;    // Ratio of Newtonian kinetic energy to the relativistic kinetic energy\n",
+"printf('\nThe ratio of Newtonian kinetic energy to the relativistic kinetic energy = %4.2f', KE_ratio);\n",
+"\n",
+"// Result\n",
+"// The total energy of the electron = 5.81e-013 J\n",
+"// The ratio of Newtonian kinetic energy to the relativistic kinetic energy = 0.08 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.1: Fringe_shift_in_the_Michelson_Morley_experiment.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.1: Page-233 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"v = 3e+004;    // Speed of earth, m/s\n",
+"d = 7;    // Effective length of each path, m\n",
+"lambda = 7000e-010;    // Wavelength of light used, m\n",
+"n = 2*d*v^2/(lambda*c^2);    // Fringe shift\n",
+"printf('\nThe expected fringe shift = %3.1f', n);\n",
+"\n",
+"// Result\n",
+"// The expected fringe shift = 0.2 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.2: Apparent_length_of_rod_relative_to_the_observer.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.2: Page-233 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"v = 3e+007;    // Speed of metre rod, m/s\n",
+"L0 = 1;    // Actual length of the rod, m\n",
+"L = L0*sqrt(1-v^2/c^2);    // Apparent length of rod from Lorentz transformation, m\n",
+"printf('\nThe apparent length of rod realtive to the observer = %5.3f m', L);\n",
+"\n",
+"// Result\n",
+"// The apparent length of rod realtive to the observer = 0.995 m "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.3: Apparent_length_of_a_meter_stick_for_different_speeds.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.3: Page-234 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"v = [c c/sqrt(2) sqrt(3)/2*c c/2 0.8*c];    // Different speeds of metre rod, m/s\n",
+"L0 = 100;    // Actual length of the rod, cm\n",
+"for i = 1:1:5\n",
+"    L = L0*sqrt(1-v(i)^2/c^2);    // Apparent length of rod from Lorentz transformation, m\n",
+"    printf('\nFor v = %4.2e m/s, L = %4.1f cm', v(i), L);\n",
+"end\n",
+"\n",
+"// Result\n",
+"// For v = 3.00e+008 m/s, L =  0.0 cm\n",
+"// For v = 2.12e+008 m/s, L = 70.7 cm\n",
+"// For v = 2.60e+008 m/s, L = 50.0 cm\n",
+"// For v = 1.50e+008 m/s, L = 86.6 cm\n",
+"// For v = 2.40e+008 m/s, L = 60.0 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.4: Lorentz_transformations_applied_to_a_rigid_bar.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.4: Page-235-236 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"// Part (a)\n",
+"v = 0.98*c ;    // Speed of the rigid bar, m/s\n",
+"L2 = 1.5;    // Length of the rigid bar in S_prime frame, m\n",
+"L1 = L2*sqrt(1-v^2/c^2);    // Apparent length of rod from Lorentz transformation, m\n",
+"theta2 = 45;    // Angle which the bar makes w.r.t. x-aixs in S_prime frame, degree\n",
+"theta1 = atand(tand(theta2)/sqrt(1-v^2/c^2));    // Orientation of bar relative to S frame, degree\n",
+"printf('\nThe orientation of the %d m bar relative to S frame = %4.1f degree', L2, theta1);\n",
+"// Part(b)\n",
+"v = 0.6*c ;    // Speed of the rigid bar, m/s\n",
+"L2 = 5;    // Length of the rigid bar in S_prime frame, m\n",
+"L1 = L2*sqrt(1-v^2/c^2);    // Apparent length of rod from Lorentz transformation, m\n",
+"theta2 = 30;    // Angle which the bar makes w.r.t. x-aixs in S_prime frame, degree\n",
+"theta1 = atand(tand(theta2)/sqrt(1-v^2/c^2));    // Orientation of bar relative to S frame, degree\n",
+"printf('\nThe orientation of the %d m bar relative to S frame = %4.1f degree', L2, theta1);\n",
+"\n",
+"// Result\n",
+"// The orientation of the 1 m bar relative to S frame = 78.7 degree\n",
+"// The orientation of the 5 m bar relative to S frame = 35.8 degree "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.5: Velocity_of_pi_meso.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.5: Page-236 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"t0 = 2.5e-008;    // Proper life time of pi-meson, s\n",
+"t = 2.5e-007;    // MEan life time of pi-meson, s\n",
+"// As t = t0/(sqrt(1-v^2/c^2)), solving for v\n",
+"v = sqrt(1-(t0/t)^2)*c;    // Velocity of pi meson, m/s\n",
+"printf('\nThe velocity of pi meson = %5.3f c = %4.2e m/s', v/c, v);\n",
+"\n",
+"// Result\n",
+"// The velocity of pi meson = 0.995 c = 2.98e+008 m/s "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.6: Relative_speed_of_the_ships_as_measured_by_an_observer.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.6: Page-237 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"v = 0.8*c;    // Speed of the first spaceship, m/s\n",
+"u_prime = 0.9*c;    // Speed of the second spaceship, m/s\n",
+"u = (u_prime+v)/(1+u_prime*v/c^2);    // Relative speed of the ships as measured by the observer on either one from Velocity addition rule, m/s\n",
+"printf('\nThe relative speed of the ships as measured by an observer in either one = %5.3f c = %4.2e m/s', u/c, u);\n",
+"\n",
+"// Result\n",
+"// The relative speed of the ships as measured by an observer in either one = 0.988 c = 2.97e+008 m/s "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.7: Velocity_of_one_particle_relative_to_the_other.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.7: Page-237 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"v = 0.9*c;    // Speed of the first particle, m/s\n",
+"u_prime = 0.9*c;    // Speed of the oppositely moving second particle, m/s\n",
+"u = (u_prime+v)/(1+u_prime*v/c^2);    // Velocity of one particle relative to the other from Velocity addition rule, m/s\n",
+"printf('\nThe velocity of one particle relative to the other = %5.3f c = %4.2e m/s', u/c, u);\n",
+"\n",
+"// Result\n",
+"// The velocity of one particle relative to the other = 0.994 c = 2.98e+008 m/s "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.8: Velocity_of_the_rocket_as_observed_from_the_earth.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.8: Page-237 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"// Case 1: when velocity of firing is away from the earth\n",
+"v = 0.5*c;    // Speed of the rocket away from the earth, m/s\n",
+"u_prime = 0.8*c;    // Speed of the outgoing spaceship relative to earth, m/s\n",
+"u = (u_prime+v)/(1+u_prime*v/c^2);    // Velocity of rocket moving away relative to the earth, m/s\n",
+"printf('\nThe velocity of rocket moving away relative to the earth = %4.2f c = %4.2e m/s', u/c, u);\n",
+"// Case 2: when velocity of firing is towards the earth\n",
+"v = 0.5*c;    // Speed of the rocket moving towards the earth, m/s\n",
+"u_prime = -0.8*c;    // Speed of the outgoing spaceship relative to earth, m/s\n",
+"u = (u_prime+v)/(1+u_prime*v/c^2);    // Velocity of approaching rocket relative to the earth, m/s\n",
+"printf('\nThe velocity of approaching rocket relative to the earth = %3.1f c = %3.1e m/s', u/c, u);\n",
+"\n",
+"// Result\n",
+"// The velocity of rocket moving away relative to the earth = 0.93 c = 2.79e+008 m/s\n",
+"// The velocity of approaching rocket relative to the earth = -0.5 c = -1.5e+008 m/s "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.9: Velocity_of_the_particle_when_its_total_energy_is_thrice_its_rest_energy.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex4.9: Page-237 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"E0 = 1;    // Assume the rest energy of the particle to be unity\n",
+"E = 3*E0;    // Total energy of the particle\n",
+"v = sqrt(1-(E0/E)^2)*c;    // Velocity of the particle from relativistic variation of mass with speed, m/s\n",
+"printf('\nThe velocity of the particle when its total energy is thrice its rest energy = %5.3e cm/s', v);\n",
+"\n",
+"// Result\n",
+"// The velocity of the particle when its total energy is thrice its rest energy = 2.828e+008 cm/s "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Engineering_Physics_by_D_C_Ghosh/5-Quantum_Mechanics.ipynb b/Engineering_Physics_by_D_C_Ghosh/5-Quantum_Mechanics.ipynb
new file mode 100644
index 0000000..b842eda
--- /dev/null
+++ b/Engineering_Physics_by_D_C_Ghosh/5-Quantum_Mechanics.ipynb
@@ -0,0 +1,841 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 5: Quantum Mechanics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.10: Planck_constant_and_threshold_wavelength_of_metal.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.10: Page-288 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"KE1 = 3.62e-019;    // Maximum kinetic energy of photoelectrons with first wavelength, eV\n",
+"lambda1 = 3000;    // First wavelength of incident radiation, angstrom\n",
+"KE2 = 0.972e-019;    // Maximum kinetic energy of photoelectrons with second wavelength, eV\n",
+"lambda2 = 5000;    // Second wavelength of incident radiation, angstrom\n",
+"A = [c/lambda1, -1; c/lambda2, -1];    // Declare a square matrix as per Einstein's Photoelectric relation, KE = h*c/lambda - phi\n",
+"B = [KE1; KE2];    // Put KEs in a column matrix\n",
+"X = inv(A)*B;    // Apply inverse multiplication of a matrix to fing h and phi\n",
+"lambda0 = X(1)*1e-010*c/X(2);    // Threshold wavelength of metal, m\n",
+"printf('\nh = %4.2e Js\nphi = %1.0e J', X(1)*1e-010, X(2));\n",
+"printf('\nThe threshold wavelength of metal = %d angstrom', ceil(lambda0/1e-010));\n",
+"\n",
+"// Result\n",
+"// h = 6.62e-034 Js\n",
+"// phi = 3e-019 J\n",
+"// The threshold wavelength of metal = 6620 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.11: Energy_and_wavelength_of_incident_photon.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.11: Page-288 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"e = 1.6e-019;    // Energy equivalent of 1 eV, J\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"m0 = 9.1e-031;    // Rest mass of an electron, kg\n",
+"alpha = 90;    // Scattering angle for X-ray photon, degree\n",
+"d_lambda = h/(m0*c)*(1-cosd(alpha));    // Wavelength shift after collision, m\n",
+"lambda = d_lambda;    // Wavelength of the incident photon according to the condition, m\n",
+"E = h*c/(lambda*e*1e+006);    // Energy of the incident photon, MeV\n",
+"printf('\nThe wavelength of the incident photon = %6.4e m', lambda);\n",
+"printf('\nThe energy of the incident photon = %4.2f MeV', E);\n",
+"\n",
+"// Result\n",
+"// The wavelength of the incident photon = 2.4249e-012 m\n",
+"// The energy of the incident photon = 0.51 MeV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.12: Energy_lost_by_an_X_ray_photon_in_collsion_with_an_electron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.12: Page-289 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"e = 1.602e-019;    // Energy equivalent of 1 eV, J\n",
+"h = 6.6e-034;    // Planck's constant, Js\n",
+"lambda = 0.1;    // Wavelength of X ray photon, angstrom\n",
+"m0 = 9.1e-031;    // Rest mass of an electron, kg\n",
+"alpha = 90;    // Scattering angle for X-ray photon, degree\n",
+"d_lambda = h/(m0*c*1e-010)*(1-cosd(alpha));    // Wavelength shift after collision, angstrom\n",
+"lambda_prime = lambda + d_lambda;    // Wavelength of the scattered photon, angstrom\n",
+"dE = h*c*1e+010/e*(1/lambda - 1/lambda_prime);    // Energy lost by the X ray photon by collision, eV\n",
+"printf('\nThe energy lost by the X ray photon by collision = %4.1f KeV', dE/1e+003);\n",
+"\n",
+"// Result\n",
+"// The energy lost by the X ray photon by collision = 24.1 KeV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.13: The_Compton_effect_stidied_at_different_scattering_angles.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.13: Page-289 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"e = 1.602e-019;    // Energy equivalent of 1 eV, J\n",
+"h = 6.6e-034;    // Planck's constant, Js\n",
+"m0 = 9.1e-031;    // Rest mass of an electron, kg\n",
+"alpha = [90 60 45 180];    // Different scattering angle for X-ray photon, degrees\n",
+"d_lambda = zeros(4);\n",
+"for i = 1:1:4\n",
+"    d_lambda(i) = h/(m0*c*1e-010)*(1-cosd(alpha(i)));    // Wavelength shift after collision, angstrom\n",
+"    printf('\nFor alpha = %d degree, d_lambda = %6.4f angstrom', alpha(i), d_lambda(i));\n",
+"end\n",
+"lambda = 0.2;    // Given wavelength of incident X-ray photon, angstrom\n",
+"lambda_prime = lambda + d_lambda(3);    // Wavelength of the scattered photon at 45 degree, angstrom\n",
+"printf('\nThe wavelength of the photon scattered at 45 degree = %5.3f angstrom', lambda_prime);\n",
+"lambda_prime = lambda + d_lambda(4);    // Maximum wavelength of the photon scattered at 180 degree, angstrom\n",
+"KE_max = h*c*1e+010*(1/lambda - 1/lambda_prime);    // Maximum kinetic energy of the recoil electron, J\n",
+"printf('\nThe maximum kinetic energy of the recoil electron = %4.2e J', KE_max);\n",
+"\n",
+"// Result\n",
+"// For alpha = 90 degree, d_lambda = 0.0242 angstrom\n",
+"// For alpha = 60 degree, d_lambda = 0.0121 angstrom\n",
+"// For alpha = 45 degree, d_lambda = 0.0071 angstrom\n",
+"// For alpha = 180 degree, d_lambda = 0.0484 angstrom\n",
+"// The wavelength of the photon scattered at 45 degree = 0.207 angstrom\n",
+"// The maximum kinetic energy of the recoil electron = 1.93e-015 J "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.15: de_Broglie_wavelength_associated_with_moving_masses.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.15: Page-292 (2008)\n",
+"clc; clear;\n",
+"h = 6.6e-034;    // Planck's constant, Js\n",
+"// For golf ball\n",
+"m = 0.046;    // Mass of the golf ball, kg\n",
+"v = 36;    // Velocity of the golf ball, m/s\n",
+"lambda = h/(m*v);    // de-Broglie wavelength associated with the moving golf ball, m\n",
+"printf('\nThe de-Broglie wavelength associated with the moving golf ball = %1.0e m', lambda);\n",
+"if lambda/1e-010 > 0.1 then\n",
+"    printf('\nThe moving golf ball may exhibit wave character.');\n",
+"end\n",
+"// For an electron\n",
+"m = 9.11e-031;    // Mass of the electron, kg\n",
+"v = 1e+007;    // Velocity of the electron, m/s\n",
+"lambda = h/(m*v);    // de-Broglie wavelength associated with the moving electron, m\n",
+"printf('\nThe de-Broglie wavelength associated with the moving electron = %3.1e m', lambda);\n",
+"if lambda/1e-010 > 0.1 then\n",
+"    printf('\nThe moving electron may exhibit wave character.');\n",
+"end\n",
+"\n",
+"// Result\n",
+"// The de-Broglie wavelength associated with the moving golf ball = 4e-034 m\n",
+"// The de-Broglie wavelength associated with the moving electron = 7.2e-011 m\n",
+"// The moving electron may exhibit wave character. "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.16: Voltage_applied_to_the_electron_microscope_to_produce_the_required_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.16: Page-292 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"e = 1.602e-019;    // Energy equivalent of 1 eV, J\n",
+"lambda = 0.40e-010; // de-Broglie wavelength associated with the moving electron, m\n",
+"m = 9.11e-031;    // Rest mass of an electron, kg\n",
+"V = (h/lambda)^2/(2*m*e);    // Voltage applied to the electron microscope to produce the required wavelength, volt\n",
+"printf('\nThe voltage applied to the electron microscope to produce the required de-Broglie wavelength = %5.1f volt', V);\n",
+"\n",
+"// Result\n",
+"// The voltage applied to the electron microscope to produce the required de-Broglie wavelength = 938.4 volt "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.18: de_Broglie_wavelength_of_a_neutron_of_given_energy.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.18: Page-293 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"e = 1.602e-019;    // Energy equivalent of 1 eV, J\n",
+"E_k = 12.8e+006;    // Energy of the moving neutron, eV\n",
+"m0 = 1.675e-027;    // Rest mass of a neutron, kg\n",
+"lambda = h/sqrt(2*m0*E_k*e) // de-Broglie wavelength associated with the moving neutron, m\n",
+"printf('\nThe de-Broglie wavelength of the moving neutron = %3.1e angstrom', lambda/1e-010);\n",
+"\n",
+"// Result\n",
+"// The de-Broglie wavelength of the moving neutron = 8.0e-005 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.19: EX5_19.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.19: Page-294 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"e = 1.602e-019;    // Energy equivalent of 1 eV, J\n",
+"m = 1.67e-027;    // Rest mass of a proton, kg\n",
+"r = 5e-015;    // Radius of the nucleus, m\n",
+"delta_x = 2*r;    // Minimum uncertainty in position of the proton, m\n",
+"delta_p = h/(2*%pi*delta_x);    // Minimum uncertainty in proton's momentum, kg-m/s\n",
+"KE = delta_p^2/(2*m);    // Minimum kinetic emergy of the proton, J\n",
+"printf('\nThe minimum uncertainty in momentum of the proton = %4.2e kg-m/s', delta_p);\n",
+"printf('\nThe minimum kinetic emergy of the proton = %5.3f MeV', KE/(e*1e+006));\n",
+"\n",
+"// Result\n",
+"// The minimum uncertainty in momentum of the proton = 1.05e-020 kg-m/s\n",
+"// The minimum kinetic emergy of the proton = 0.207 MeV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.20: Minimum_uncertainty_in_the_measurement_of_velocity_of_the_electron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.20: Page-294 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"m = 9.11e-031;    // Rest mass of a electron, kg\n",
+"delta_x = 1e-009;    // Minimum uncertainty in position of the electron, m\n",
+"delta_p_min = h/delta_x;    // Minimum uncertainty in electron's momentum, kg-m/s\n",
+"delta_v = delta_p_min/m;    // Minimum uncertainty in the measurement of velocity of the electron, m/s\n",
+"printf('\nThe minimum uncertainty in the measurement of velocity of the electron = %4.2e m/s', delta_v);\n",
+"\n",
+"// Result\n",
+"// The minimum uncertainty in the measurement of velocity of the electron = 7.27e+005 m/s "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.22: Minimum_uncertainty_in_the_position_of_the_particle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.22: Page-295 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"m = 1e-009;    // Mass of the particle, kg\n",
+"v = 1;    // Velocity of the particle, m/s\n",
+"delta_v = v*0.01/100;    // Minimum uncertainty in the velocity of the particle, m/s\n",
+"delta_x = h/(m*delta_v);    // Minimum uncertainty in the position of the particle, m \n",
+"printf('\nThe minimum uncertainty in the position of the particle = %4.2e m', delta_x);\n",
+"\n",
+"// Result\n",
+"// The minimum uncertainty in the position of the particle = 6.62e-021 m "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.23: Uncertainty_with_which_position_of_the_electron_can_be_located.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.23: Page-295 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"m = 9.1e-031;    // Mass of the electron, kg\n",
+"v = 1e+003;    // Velocity of the electron, m/s\n",
+"delta_v = v*0.05/100;    // Minimum uncertainty in the velocity of the electron, m/s\n",
+"delta_x = h/(m*delta_v);    // Minimum uncertainty in the position of the electron, m \n",
+"printf('\nThe minimum uncertainty in the position of the electron = %4.2e m', delta_x);\n",
+"\n",
+"// Result\n",
+"// The minimum uncertainty in the position of the electron = 1.45e-003 m "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.24: Minimum_uncertainty_in_energy_of_the_excited_state_of_an_atom.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.24: Page-295 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"e = 1.602e-019;    // Energy equivalent of 1 eV, J\n",
+"delta_t = 1e-008;    // Life time of excited state of an atom, s\n",
+"delta_E = h/(2*%pi*delta_t);    // Minimum uncertainty in the energy of the excited state of the atom, J \n",
+"printf('\nThe minimum uncertainty in the energy of the excited state of the atom = %3.1e eV', delta_E/e);\n",
+"\n",
+"// Result\n",
+"// The minimum uncertainty in the energy of the excited state of the atom = 6.6e-008 eV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.25: Probable_uncertainty_in_energy_and_frequency_of_gamma_ray_photon.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.25: Page-296 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"delta_t = 1e-012;    // Life time of a nucleus in the excited state, s\n",
+"delta_E = h/(2*%pi*delta_t);    // Minimum uncertainty in the energy of the excited state of the nucleus, J \n",
+"// As E = h*nu, solving for delta_nu\n",
+"delta_nu = delta_E/h;    // Minimum uncertainty in the frequency of the excited state of the nucleus, Hz\n",
+"printf('\nThe minimum uncertainty in the energy of the excited state of the nucleus = %5.3e J', delta_E);\n",
+"printf('\nThe minimum uncertainty in the frequency of the excited state of the nucleus = %4.2e MHz', delta_nu/1e+006);\n",
+"\n",
+"// Result\n",
+"// The minimum uncertainty in the energy of the excited state of the nucleus = 1.054e-022 J\n",
+"// The minimum uncertainty in the frequency of the excited state of the nucleus = 1.59e+005 MHz "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.29: Lowest_energy_of_an_electron_in_one_dimensional_force_free_region.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.29: Page-300 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"e = 1.602e-019;    // Energy equivalent of 1 eV, J\n",
+"m = 9.11e-031;    // Rest mass of the electron, kg\n",
+"l = 4e-010;    // Length of the force free region, m\n",
+"n = 1;    // Principal quantum number for lowest energy state\n",
+"E1 = n^2*h^2/(8*m*l^2);    // Lowest energy of an electron in one dimensional force free region, J\n",
+"printf('\nThe lowest energy of an electron in one dimensional force free region = %4.2f eV', E1/e);\n",
+"\n",
+"// Result\n",
+"// The lowest energy of an electron in one dimensional force free region = 2.35 eV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.2: Temperature_of_the_surface_of_su.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.2: Page-284 (2008)\n",
+"clc; clear;\n",
+"lambda_m = 4753e-010;    // Wavelength from the sun at which maximum energy is emitted, m\n",
+"b = 2.88e-003;    // Wein's constant, m-K\n",
+"T = b/lambda_m;    // Temperature of the surface of sun\n",
+"printf('\nThe temperature of the surface of sun = %d K', ceil(T));\n",
+"\n",
+"// Result\n",
+"// The temperature of the surface of sun = 6060 K "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.30: The_excited_state_energies_of_the_particle_entrapped_in_a_one_dimensional_box.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.30: Page-300 (2008)\n",
+"clc; clear;\n",
+"e = 1.602e-019;    // Energy equivalent of 1 eV, J\n",
+"E1 = 3.2e-018/e;    // Minimum energy possible for a particle entrapped in a one dimensional box, eV\n",
+"n = [1 2 3 4];    // Principal quantum number for K, L, M and N states\n",
+"printf('\nThe next three energies which the particle can have are:');\n",
+"for i = 2:1:4\n",
+"    printf('\nE%d = %d eV', i, ceil(i^2*E1));\n",
+"end\n",
+"\n",
+"// Result\n",
+"// The next three energies which the particle can have are:\n",
+"// E2 = 80 eV\n",
+"// E3 = 180 eV\n",
+"// E4 = 320 eV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.31: Probability_of_finding_the_particle_within_a_given_interval.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.31: Page-301 (2008)\n",
+"clc; clear;\n",
+"delta_x = 4;    // Interval at the centre of the box at which the probability is to be found out, angstrom\n",
+"l = 10;    // Width of one dimensional infinite height box, angstrom\n",
+"P = 2*delta_x/l;    // Probability of finding the particle within 4 angstrom interval\n",
+"printf('\nThe probability of finding the particle within the %d angstrom interval at the centre of the box = %3.1f', delta_x, P);\n",
+"\n",
+"// Result\n",
+"// The probability of finding the particle within the 4 angstrom interval at the centre of the box = 0.8 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.32: EX5_32.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.32: Page-301 (2008)\n",
+"clc; clear;\n",
+"L = 1;    // Assume the length of the box to be unity, m\n",
+"L1 = 0.4*L;    // Lower limit, m\n",
+"L2 = 0.6*L;    // Upper limit, m\n",
+"x = (L1+L2)/2;    // Mean position of particle, m\n",
+"delta_x = L2 - L1;    // Uncertainty in position of the particle, m\n",
+"for n = 1:1:3\n",
+"    P = 2/L*sin(n*%pi*x/L)^2;    // Probability density, per m\n",
+"    printf('\nFor n = %d, the probability, P = %3.1f', n, P*delta_x);\n",
+"end\n",
+"\n",
+"// Result\n",
+"// For n = 1, the probability, P = 0.4\n",
+"// For n = 2, the probability, P = 0.0\n",
+"// For n = 3, the probability, P = 0.4 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.3: Wavelength_of_maximum_intensity_of_radiation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.3: Page-284 (2008)\n",
+"clc; clear;\n",
+"b = 2.898e-003;    // Wein's constant, m-K\n",
+"T = 3000 + 273;    // Temperature of the source, K\n",
+"lambda_m = b/T;    // Wavelength of maximum intensity of radiation emitted from the source, m\n",
+"printf('\nThe wavelength of maximum intensity of radiation emitted from the source = %d angstrom', lambda_m/1e-010);\n",
+"\n",
+"// Result\n",
+"// The wavelength of maximum intensity of radiation emitted from the source = 8854 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.4: Kinetic_energy_of_the_ejected_photoelectrons.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.4: Page-285 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"lambda = 2300e-010;    // Thereshold wavelength for tungsten, m\n",
+"phi = h*c/lambda;    // Work function for tungsten, J\n",
+"lambda = 1800e-010;    // Wavelength of incident radiation, m\n",
+"E = h*c/lambda;    // Energy of the incidnt radiation, J\n",
+"KE = E - phi;    // Kinetic energy of the ejected photoelectrons, J\n",
+"printf('\nThe kinetic energy of the ejected photoelectrons = %3.1f eV', KE/1.6e-019);\n",
+"\n",
+"// Result\n",
+"// The kinetic energy of the ejected photoelectrons = 1.5 eV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.5: Possibility_of_electron_emission_with_the_given_incident_wavelengths.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.5: Page-285 (2008)\n",
+"clc; clear;\n",
+"function [] = check_energy(E, L)\n",
+"phi = 4.8;    // Work function for tungsten, eV\n",
+"    if E > phi then\n",
+"        printf('\nThe wavelength %d angstrom will be able to liberate an electron.', ceil(L/1e-010));\n",
+"    else\n",
+"        printf('\nThe wavelength %d angstrom will not be able to liberate an electron.', ceil(L/1e-010));    \n",
+"    end\n",
+"endfunction\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"// Case 1\n",
+"lambda = 2000e-010;    // Wavelength of incident radiation, m\n",
+"E = h*c/(lambda*1.6e-019);    // Energy of the incidnt radiation, eV\n",
+"check_energy(E, lambda);    // Check for the wavelength\n",
+"// Case 2\n",
+"lambda = 5000e-010;    // Wavelength of incident radiation, m\n",
+"E = h*c/(lambda*1.6e-019);    // Energy of the incidnt radiation, eV\n",
+"check_energy(E, lambda);    // Check for the wavelength\n",
+"\n",
+"// Result\n",
+"// The wavelength 2000 angstrom will be able to liberate an electron.\n",
+"// The wavelength 5000 angstrom will not be able to liberate an electron. "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.6: Velocity_of_emitted_photoelectrons.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.6: Page-286 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"e = 1.6e-019;    // Energy quivalent of 1 eV, J\n",
+"phi = 2.28*e;    // Work function for material, J\n",
+"m = 9.1e-031;    // Mass of an electron, kg\n",
+"lambda = 3000e-010;    // Wavelength of incident radiation, m\n",
+"E = h*c/lambda;    // Energy of the incidnt radiation, J\n",
+"KE = E - phi;    // Kinetic energy of the ejected photoelectrons, J\n",
+"v = sqrt(2*KE/m);    // Velocity of emitted electron, m/s\n",
+"printf('\nThe velocity of the emitted electron = %4.2e m/s', v);\n",
+"\n",
+"// Result\n",
+"// The velocity of the emitted electron = 8.08e+005 m/s "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.7: A_photosensitive_material_emitting_photoelectrons.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.7: Page-286 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"e = 1.6e-019;    // Energy quivalent of 1 eV, J\n",
+"phi = 4.2*e;    // Work function for material, J\n",
+"lambda = 2000e-010;    // Wavelength of incident radiation, m\n",
+"E = h*c/lambda;    // Energy of the incidnt radiation, J\n",
+"KE_fast = (E - phi)/e;    // Kinetic energy of the fastest photoelectron, eV\n",
+"KE_slow = 0;    // Kinetic energy of the slowest photoelectron, eV\n",
+"printf('\nThe kinetic energy of the fastest photoelectron = %d eV', KE_fast);\n",
+"printf('\nThe kinetic energy of the slowest photoelectron = %d eV', KE_slow);\n",
+"V = (E - phi)/e;    // Stopping potential, V\n",
+"printf('\nThe stopping potential = %d volt', V);\n",
+"\n",
+"// Result\n",
+"// The kinetic energy of the fastest photoelectron = 2 eV\n",
+"// The kinetic energy of the slowest photoelectron = 0 eV\n",
+"// The stopping potential = 2 volt "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.8: Maximum_wavelength_of_radiation_which_would_start_the_emission_of_photoelectrons.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.8: Page-287 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-027;    // Planck's constant, erg-s\n",
+"c = 3e+010;    // Speed of light, cm/s\n",
+"phi = 3.31e-012;    // Work function for material, erg\n",
+"lambda0 = h*c/phi;    // Wavelength of incident radiation, cm\n",
+"printf('\nThe maximum wavelength of radiation which would start the emission of photoelectrons = %d angstrom', lambda0/1e-008);\n",
+"\n",
+"// Result\n",
+"// The maximum wavelength of radiation which would start the emission of photoelectrons = 6000 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.9: Potassium_surface_exposed_to_UV_radiatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex5.9: Page-287 (2008)\n",
+"clc; clear;\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"e = 1.6e-019;    // Energy quivalent of 1 eV, J\n",
+"phi = 2.1*e;    // Work function for material, J\n",
+"lambda = 3500e-010;    // Wavelength of incident UV radiation, m\n",
+"E = 1e-004;    // Energy incident per sec on 1 Sq. cm of potassium surface, J\n",
+"eta = 0.5/100;    // Efficiency of potassium surface\n",
+"KE = (h*c/lambda-phi)/e;    // Maximum kinetic energy of the ejected photoelectrons, eV\n",
+"N = eta*E/(KE*e);    // Number of photoelectrons emitted per second per Sq. cm of potassium surface\n",
+"printf('\nThe maximum kinetic energy of the incidnt radiation = %4.2f eV', KE);\n",
+"printf('\nThe number of photoelectrons emitted per second per Sq. cm of potassium surface = %4.2e', N);\n",
+"\n",
+"// Result\n",
+"// The maximum kinetic energy of the incidnt radiation = 1.45 eV\n",
+"// The number of photoelectrons emitted per second per Sq. cm of potassium surface = 2.16e+012 "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Engineering_Physics_by_D_C_Ghosh/6-Classical_Statistics_and_Quantum_Statistics.ipynb b/Engineering_Physics_by_D_C_Ghosh/6-Classical_Statistics_and_Quantum_Statistics.ipynb
new file mode 100644
index 0000000..682b90d
--- /dev/null
+++ b/Engineering_Physics_by_D_C_Ghosh/6-Classical_Statistics_and_Quantum_Statistics.ipynb
@@ -0,0 +1,292 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 6: Classical Statistics and Quantum Statistics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.10: Number_of_microstates_formed_by_particles_obeying_Fermi_Dirac_statistics.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex6.10: Page-350 (2008)\n",
+"clc; clear;\n",
+"g1 = 8, g2 = 10;    // Total number of cells in the first and the second compartments respectively\n",
+"n1 = 3, n2 = 4;    // Given number of cells in the first and the second compartments respectively for given macrostate\n",
+"W_34 = factorial(g1)/(factorial(n1)*factorial(g1 - n1))*factorial(g2)/(factorial(n2)*factorial(g2 - n2));    // Total number of microstates in the macrostate (3, 4)\n",
+"printf('\nThe total number of microstates in the macrostate (%d, %d) = %d', n1, n2, W_34);\n",
+"\n",
+"// Result\n",
+"// The total number of microstates in the macrostate (3, 4) = 11760 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.11: Fermi_energy_and_internal_energy_for_metallic_silver_at_0_K.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex6.11: Page-351 (2008)\n",
+"clc; clear;\n",
+"h = 6.6e-034;    // Planck's constant, Js\n",
+"m = 9.1e-031;    // Mass of an electron, kg\n",
+"e = 1.6e-019;    // Energy equivalent of 1 eV, J\n",
+"rho = 10.5;    // Density of silver, g/cc\n",
+"A = 108;    // Atomic weight of Ag, g/mole\n",
+"N_A = 6.023e+023;    // Avogadro's number\n",
+"E_F0 = h^2/(8*m)*(3*N_A*rho*1e+006/(%pi*A))^(2/3);     // Fermi energy of silver at 0 K, J\n",
+"U = 3/5*(N_A*rho*1e+006/A)*E_F0;    // Internal energy of the electron gas per unit volume at 0 K, J/metre-cube\n",
+"printf('\nThe Fermi energy of silver at 0 K = %3.1f eV', E_F0/e);\n",
+"printf('\nThe internal energy of the electron gas per unit volume at 0 K = %4.2e J/cubic-metre', U);\n",
+"\n",
+"// Result\n",
+"// The Fermi energy of silver at 0 K = 5.5 eV\n",
+"// The internal energy of the electron gas per unit volume at 0 K = 3.07e+010 J/cubic-metre "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.12: Number_of_conduction_electrons_per_cc_in_silver_at_0_K.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex6.12: Page-351 (2008)\n",
+"clc; clear;\n",
+"h = 6.6e-034;    // Planck's constant, Js\n",
+"m = 9.1e-031;    // Mass of an electron, kg\n",
+"e = 1.6e-019;    // Energy equivalent of 1 eV, J\n",
+"E_F0 = 5.48;     // Fermi energy of silver at 0 K, eV\n",
+"N_bar = (8*m/h^2)^(3/2)*%pi/3*(E_F0*e)^(3/2);    // Number density of conduction electrons in silver at 0 K, per cc\n",
+"printf('\nThe number density of conduction electrons in silver at 0 K = %3.1e per cc', N_bar*1e-006);\n",
+"\n",
+"// Result\n",
+"// The number density of conduction electrons in silver at 0 K = 5.9e+022 per cc "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.13: Fermi_energy_of_conduction_electrons_in_cesium.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex6.13: Page-351 (2008)\n",
+"clc; clear;\n",
+"h = 6.6e-034;    // Planck's constant, Js\n",
+"m = 9.1e-031;    // Mass of an electron, kg\n",
+"e = 1.6e-019;    // Energy equivalent of 1 eV, J\n",
+"E_F0_Be = 14.44      // Fermi energy of Be at 0 K, eV\n",
+"N_bar_Be = 24.2e+022;   // Number density of conduction electrons in Be at 0 K, per cc\n",
+"N_bar_Cs = 0.91e+022;    // Number density of conduction electrons in Cs at 0 K, per cc\n",
+"E_F0_Cs = E_F0_Be*(N_bar_Cs/N_bar_Be)^(2/3);    // Fermi energy of conduction electrons in cesium, eV\n",
+"printf('\nThe Fermi energy of conduction electrons in cesium = %5.3f eV', E_F0_Cs);\n",
+"\n",
+"// Result\n",
+"// The Fermi energy of conduction electrons in cesium = 1.621 eV \n",
+"// The answer is given wrongly in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.1: Probability_of_distribution_of_distinguishable_particles.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex6.1: Page-345 (2008)\n",
+"clc; clear;\n",
+"n = 14;    // Total number of particles\n",
+"C = 2;    // Total number of compartments\n",
+"N_micro = C^n;    // Total number of microstates\n",
+"n1 = [10 7 14];    // Set of number of particles in first compartment\n",
+"n2 = [4 7 0];    // Set of number of particles in second compartment\n",
+"for i = 1:1:3\n",
+"    W = factorial(n1(i) + n2(i))/(factorial(n1(i))*factorial(n2(i)));\n",
+"    P = W/N_micro;\n",
+"    printf('\nThe probability of microstate (%d, %d) = %8.6f', n1(i), n2(i), P);\n",
+"end\n",
+"\n",
+"// Result\n",
+"// The probability of microstate (10, 4) = 0.061096\n",
+"// The probability of microstate (7, 7) = 0.209473\n",
+"// The probability of microstate (14, 0) = 0.000061 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6: Most_probable_distribution_for_total_energy.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex6.6: Page-348 (2008)\n",
+"clc; clear;\n",
+"MAX = 10;\n",
+"// Look for all the possible set of values for n1, n2 and n3\n",
+"printf('\nThe most probable distribution is for ');\n",
+"for i = 0:1:5  \n",
+"    for j = 0:1:5\n",
+"        for k = 0:1:5\n",
+"      // Check for the condition and avoid repetition of set of values\n",
+"            if ((i + j + k) == 5) & ((j+2*k) == 3) then \n",
+"                W = factorial(i + j + k)/(factorial(i)*factorial(j)*factorial(k));\n",
+"                if W > MAX then\n",
+"                   printf('\nn1 = %d, n2 = %d and n3 = %d', i, j, k);\n",
+"                end\n",
+"            end\n",
+"        end\n",
+"    end\n",
+"end\n",
+"\n",
+"// Result\n",
+"// The most probable distribution is for \n",
+"// n1 = 3, n2 = 1 and n3 = 1 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.8: Probability_for_a_Maxwell_Boltzmann_system_to_be_in_given_states.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex6.8: Page-349 (2008)\n",
+"clc; clear;\n",
+"k = 1.38e-016;    // Boltzmann constant, erg/K\n",
+"T = 100;    // Given temperature, K\n",
+"E1 = 0;    // Energy of the first state, erg\n",
+"E2 = 1.38e-014;    // Energy of the second state, erg\n",
+"E3 = 2.76e-014;    // Energy of the third state, erg\n",
+"g1 = 2, g2 = 5, g3 = 4;    // Different ways of occuring for E1, E2 and E3 states\n",
+"P1 = g1*exp(-E1/(k*T));    // Probability of occurence of state E1\n",
+"P2 = g2*exp(-E2/(k*T));    // Probability of occurence of state E2\n",
+"P3 = g3*exp(-E3/(k*T));    // Probability of occurence of state E3\n",
+"PE_3 = P3/(P1+P2+P3);    // Probability for the system to be in any one microstates of E3\n",
+"P0 = P1/(P1+P2+P3);    // Probability for the system to be in ground state\n",
+"printf('\nThe probability for the system to be in any one microstates of E3 = %6.4f', PE_3);\n",
+"printf('\nThe probability for the system to be in ground state = %5.3f', P0);\n",
+"\n",
+"// Result\n",
+"// The probability for the system to be in any one microstates of E3 = 0.1236\n",
+"// The probability for the system to be in ground state = 0.457 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.9: Number_of_microstates_in_the_given_macostate_of_a_Fermi_Dirac_system.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex6.9: Page-350 (2008)\n",
+"clc; clear;\n",
+"g1 = 6, g2 = 8;    // Total number of cells in the first and the second compartments respectively\n",
+"n1 = 2, n2 = 3;    // Given number of cells in the first and the second compartments respectively for given macrostate\n",
+"W_23 = factorial(g1)/(factorial(n1)*factorial(g1 - n1))*factorial(g2)/(factorial(n2)*factorial(g2 - n2));    // Total number of microstates in the macrostate (2, 3)\n",
+"printf('\nThe total number of microstates in the macrostate (%d, %d) = %d', n1, n2, W_23);\n",
+"\n",
+"// Result\n",
+"// The total number of microstates in the macrostate (2, 3) = 840 "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Engineering_Physics_by_D_C_Ghosh/7-Classical_Statistics_and_Quantum_Statistics.ipynb b/Engineering_Physics_by_D_C_Ghosh/7-Classical_Statistics_and_Quantum_Statistics.ipynb
new file mode 100644
index 0000000..30b7e25
--- /dev/null
+++ b/Engineering_Physics_by_D_C_Ghosh/7-Classical_Statistics_and_Quantum_Statistics.ipynb
@@ -0,0 +1,594 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 7: Classical Statistics and Quantum Statistics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.10: Interplanar_spacing_for_a_set_of_planes_in_a_cubic_lattice.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.10: Page-380 (2008)\n",
+"clc; clear;\n",
+"h = 3; k = 2; l = 1; // Miller Indices for planes in a cubic crystal\n",
+"a = 4.21D-10;    // Interatomic spacing, m\n",
+"d = a/(h^2+k^2+l^2)^(1/2);  // The interplanar spacing for cubic crystals, m\n",
+"printf('\nThe interplanar spacing between consecutive (321) planes = %3.1e m', d);\n",
+"\n",
+"// Result\n",
+"// The interplanar spacing between consecutive (321) planes = 1.1e-010 m "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.11: Determining_Planck_constant_from_given_set_of_X_ray_data.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.11: Page-380 (2008)\n",
+"clc; clear;\n",
+"e = 1.6e-019;    // The energy equivalent of 1 eV, J\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"V = [30 44 50 200];    // Operating voltages of X ray, kV\n",
+"lambda_min = [0.414 0.284 0.248 0.062];    // Minimum wavelengths of emitted continuous X rays, angstrom\n",
+"for i = 1:1:4\n",
+"    h = e*V(i)*1e+003*lambda_min(i)*1e-010/c;    // Planck's constant, Js\n",
+"    printf('\nFor V = %d kV and lambda_min = %5.3f angstrom, h = %4.2e Js', V(i), lambda_min(i), h);\n",
+"end\n",
+"     \n",
+"// Result\n",
+"// For V = 30 kV and lambda_min = 0.414 angstrom, h = 6.62e-034 Js\n",
+"// For V = 44 kV and lambda_min = 0.284 angstrom, h = 6.66e-034 Js\n",
+"// For V = 50 kV and lambda_min = 0.248 angstrom, h = 6.61e-034 Js\n",
+"// For V = 200 kV and lambda_min = 0.062 angstrom, h = 6.61e-034 Js "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.12: Maximum_speed_of_striking_electron_and_the_shortest_wavelength_of_X_ray_produced.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.12: Page-381 (2008)\n",
+"clc; clear;\n",
+"e = 1.6e-019;    // The energy equivalent of 1 eV, J\n",
+"m = 9.11e-031;    // Rest mass of an electron, kg\n",
+"h = 6.62e-034;    // Planck's constant, Js\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"V = [20 100];    // Operating voltages of X ray, kV\n",
+"for i = 1:1:2\n",
+"    v = sqrt(2*e*V(i)*1e+003/m);    // Maximum striking speed of the electron, m/s\n",
+"    lambda_min = c*h/(e*V(i)*1e+003*1e-010);    // Minimum wavelength of emitted continuous X rays, angstrom\n",
+"    printf('\nFor V = %d kV:', V(i));\n",
+"    printf('\nThe maximum striking speed of the electron = %5.2e m/s', v);\n",
+"    printf('\nThe minimum wavelength of emitted continuous X rays = %5.3f angstrom\n', lambda_min);\n",
+"end\n",
+"     \n",
+"// Result\n",
+"// For V = 20 kV:\n",
+"// The maximum striking speed of the electron = 8.38e+007 m/s\n",
+"// The minimum wavelength of emitted continuous X rays = 0.621 angstrom\n",
+"//\n",
+"// For V = 100 kV:\n",
+"// The maximum striking speed of the electron = 1.87e+008 m/s\n",
+"// The minimum wavelength of emitted continuous X rays = 0.124 angstrom\n",
+"// There are small variation in the answers as approximations are used in the text\n",
+" "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.13: Interatomic_spacing_using_Bragg_relation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.13: Page-381 (2008)\n",
+"clc; clear;\n",
+"n = 1;    // Order of diffraction\n",
+"lambda = 1.75e-010;    // Wavelength of X rays, m\n",
+"h = 1, k = 1, l = 1;    // Miller indices for the set of planes\n",
+"theta = 30;    // Bragg's angle, degree\n",
+"// As from Bragg's law, 2*d*sind(theta) = n*lambda and d = a/sqrt(h^2+k^2+l^2). solving for a we have\n",
+"a = sqrt(h^2+k^2+l^2)*n*lambda/(2*sind(theta)*1e-010);    // Interatomic spacing of the crystal, angstrom\n",
+"printf('\nThe interatomic spacing of the crystal = %5.3f angstrom', a);\n",
+"\n",
+"// Result\n",
+"// The interatomic spacing of the crystal = 3.031 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.14: Value_of_Planck_constant_from_Bragg_relation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.14: Page-382 (2008)\n",
+"clc; clear;\n",
+"e = 1.6e-019;    // The energy equivalent of 1 eV, J\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"n = 1;    // Order of diffraction\n",
+"d = 2.82e-010;    // Interplanar spacing, m\n",
+"V = 9.1e+003;    // Operating voltage of X rays\n",
+"theta = 14;    // Bragg's angle, degree\n",
+"lambda = 2*d*sind(theta)/n;    // Wavelength of X rays, m\n",
+"nu = c/lambda;    // Frequency of X rays, Hz\n",
+"h = e*V/nu;    // Planck's constant, Js\n",
+"printf('\nThe value of Planck constant, h = %4.2e Js', h);\n",
+"\n",
+"// Result\n",
+"// The value of Planck constant, h = 6.62e-034 Js "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.15: Diffraction_of_X_rays_from_a_crystal.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.15: Page-382 (2008)\n",
+"clc; clear;\n",
+"e = 1.6e-019;    // The energy equivalent of 1 eV, J\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"lambda = 0.5e-010;    // Wavelength of X rays, m\n",
+"theta = 5;    // Bragg's angle, degree\n",
+"n = 1;    // Order of diffraction\n",
+"d = n*lambda/(2*sind(theta)*1e-010);    // Interplanar spacing, angstrom\n",
+"n = 2;    // Ordr of diffraction\n",
+"theta1 = asind(n*lambda/(2*d*1e-010));    // Angle at which the second maximum occur, degree\n",
+"printf('\nThe spacing between adjacent planes of the crystal = %4.2f angstrom', d);\n",
+"printf('\nThe angle at which the second maximum occur = %5.2f degree', theta1);\n",
+"\n",
+"// Result\n",
+"// The spacing between adjacent planes of the crystal = 2.87 angstrom\n",
+"// The angle at which the second maximum occur = 10.04 degree "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.16: Wavelength_of_X_rays_from_grating_space_of_the_rock_salt.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.16: Page-383 (2008)\n",
+"clc; clear;\n",
+"M = 58.5    // Gram atomic mass of NaCl, kg/mole\n",
+"N = 6.023e+026;    // Avogadro's number per kmol\n",
+"rho = 2.17e+003;    // Density of NaCl, kg/metre-cube\n",
+"m = M/N;    // Mass of each NaCl molecule, g\n",
+"V = m/rho;    // Volume of each NaCl molecule, metre-cube\n",
+"d = (V/2)^(1/3)/1e-010;    // Atomic apacing in the NaCl crystal, angstrom\n",
+"theta = 26;    // Bragg's angle, degree\n",
+"n = 2;    // Order of diffraction\n",
+"lambda = 2*d*sind(theta)/n;    // Wavelength of X rays, m\n",
+"printf('\nThe grating spacing of rock salt = %4.2f angstrom', d);\n",
+"printf('\nThe wavelength of X rays = %4.2f angstrom', lambda);\n",
+"\n",
+"// Result\n",
+"// The grating spacing of rock salt = 2.82 angstrom\n",
+"// The wavelength of X rays = 1.24 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.17: Diffraction_of_X_rays_by_the_calcite_crystal.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.17: Page-383 (2008)\n",
+"clc; clear;\n",
+"d = 3.02945e-010;    // Atomic apacing in the calcite crystal, m\n",
+"lambda_alpha = 0.563e-010;    // Wavelength of the K-alpha line of Ag, m\n",
+"n = 1;    // Order of diffraction\n",
+"theta = asind(n*lambda_alpha/(2*d));    // Angle of reflection for the first order, degree\n",
+"theta_max = 90;    // Angle of reflection for the highest order, degree\n",
+"n = 2*d*sind(theta_max)/lambda_alpha;    // The highest order for which the line may be observed\n",
+"printf('\nThe angle of reflection for the first order = %4.2f degree', theta);\n",
+"printf('\nThe highest order for which the line may be observed = %d', n);\n",
+"\n",
+"// Result\n",
+"// The angle of reflection for the first order = 5.33 degree\n",
+"// The highest order for which the line may be observed = 10 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.18: Interatomic_spacing_for_given_crystal_planes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.18: Page-384 (2008)\n",
+"clc; clear;\n",
+"lambda = 1.8e-010;    // Wavelength of the X rays, m\n",
+"n = 1;    // Order of diffraction\n",
+"theta = 60;    // Angle of diffraction for the first order, degree\n",
+"d = n*lambda/(2*sind(theta));    // Interplanar spacing, m\n",
+"// Since for a simple cubic lattice, d_111 = d = a/sqrt(3), solving for a\n",
+"a = sqrt(3)*d;    // The interatomic spacing for the given crystal planes, m\n",
+"printf('\nThe interatomic spacing for the given crystal planes, a = %3.1f angstrom', a/1e-010);\n",
+"\n",
+"// Result\n",
+"// The interatomic spacing for the given crystal planes, a = 1.8 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.19: Smallest_angle_between_the_crystal_plane_and_the_X_ray_beam.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.19: Page-384 (2008)\n",
+"clc; clear;\n",
+"function [d, m] = deg2degmin(theta)\n",
+"    d = int(theta);\n",
+"    m = (theta-d)*60;\n",
+"endfunction\n",
+"h = 6.626e-034;    // Planck's constant, Js\n",
+"e = 1.6e-019;    // The energy equivalent of 1 eV, J\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"V = 50e+003;    // Operating voltage of X ray, V\n",
+"lambda_min = h*c/(e*V);    // Minimum wavelength of emitted continuous X rays, angstrom\n",
+"n = 1;    // Order of diffraction\n",
+"d = 3.02945e-010;    // Interplanar spacing, m\n",
+"theta = asind(n*lambda_min/(2*d));    // The smallest angle between the crystal plane and the X ray beam, degree\n",
+"[deg , m] = deg2degmin(theta);\n",
+"printf('\nThe smallest angle between the crystal plane and the X ray beam = %d degree %d min', deg, m);\n",
+"\n",
+"// Result\n",
+"// The smallest angle between the crystal plane and the X ray beam = 2 degree 21 min "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.1: Atomic_packing_fractions_of_SC_FCC_and_BCC_unit_cells.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.1: Page-376 (2008)\n",
+"clc; clear;\n",
+"a = poly(0, 'a');    // Lattice parameter for a cubic unit cell, m\n",
+"// For simple cubic cell\n",
+"n = 1;    // Number of atoms per simple cubic unit cell\n",
+"r = a/2;    // Atomic radius for a simple cubic cell, m\n",
+"f = pol2str(int(numer(n*4/3*%pi*r^3/a^3)*100));    // Atomic packing fraction for a simple cubic cell\n",
+"printf('\nFor simple cubic cell, f = %s percent', f);\n",
+"// For face centered cubic cell\n",
+"n = 2;    // Number of atoms per face centered cubic unit cell\n",
+"r = sqrt(3)/4*a;    // Atomic radius for a face centered cubic cell, m\n",
+"f = pol2str(int(numer(n*4/3*%pi*r^3/a^3)*100));    // Atomic packing fraction for a face centered cubic cell\n",
+"printf('\nFor face centered cubic cell, f = %s percent', f);\n",
+"// For body centered cubic cell\n",
+"n = 4;    // Number of atoms per body centered cubic unit cell\n",
+"r = a/(2*sqrt(2));    // Atomic radius for a body centered cubic cell, m\n",
+"f = pol2str(int(numer(n*4/3*%pi*r^3/a^3)*100));    // Atomic packing fraction for a body centered cubic cell\n",
+"printf('\nFor body centered cubic cell, f = %s percent', f);\n",
+"\n",
+"// Result\n",
+"// For simple cubic cell, f =  52 percent\n",
+"// For face centered cubic cell, f =  68 percent\n",
+"// For body centered cubic cell, f =  74 percent "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.3: Distance_between_two_adjacent_atoms_in_the_NaCl.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.3: Page-377 (2008)\n",
+"clc; clear;\n",
+"M = 58.46;    // Gram atomic mass of NaCl, g/mole\n",
+"N = 6.023e+023;    // Avogadro's number\n",
+"rho = 2.17;    // Density of NaCl, g/cc\n",
+"m = M/N;    // Mass of each NaCl molecule, g\n",
+"n = rho/m;    // Number of NaCl molecules per unit volume, molecules/cc\n",
+"N = 2*n;    // Number of atoms per unit volume, atoms/cc\n",
+"a = (1/N)^(1/3);    // Distance between two adjacent atoms in the NaCl, cm\n",
+"printf('\nThe distance between two adjacent atoms in the NaCl = %4.2f angstrom', a/1e-008);\n",
+"\n",
+"// Result\n",
+"// The distance between two adjacent atoms in the NaCl = 2.82 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.4: Type_of_unit_cell_of_Cs.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.4: Page-377 (2008)\n",
+"clc; clear;\n",
+"function p = find_cell_type(x)\n",
+"    if x == 1 then\n",
+"        p = 'simple cubic';\n",
+"    end    \n",
+"    if x == 2 then\n",
+"        p = 'body centered';\n",
+"    end    \n",
+"    if x == 4 then \n",
+"        p = 'face centered';        \n",
+"    end\n",
+"endfunction\n",
+"M = 130;    // Gram atomic weight of Cs, g/mole\n",
+"N = 6.023e+023;    // Avogadro's number\n",
+"rho = 2;    // Density of Cs, g/cc\n",
+"a = 6e-008;    // Distance between two adjacent atoms in the Cs, cm\n",
+"m = M/N;    // Mass of each Cs atom, g\n",
+"x = rho*a^3*N/M;    // Number of Cs atoms in cubic unit cell\n",
+"c_type = find_cell_type(int(x));    // Call function to determine the type of cell\n",
+"printf('\nThe cubic unit cell of Cs is %s.', c_type);\n",
+"\n",
+"// Result\n",
+"// The cubic unit cell of Cs is body centered. "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.5: Miller_indices_of_given_planes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.5: Page-378 (2008)\n",
+"clc; clear;\n",
+"m = 2; n = 3; p = 6; // Coefficients of intercepts along three axes\n",
+"m_inv = 1/m;        // Reciprocate the first coefficient\n",
+"n_inv = 1/n;        // Reciprocate the second coefficient\n",
+"p_inv = 1/p;        // Reciprocate the third coefficient\n",
+"mul_fact = double(lcm(int32([m,n,p]))); // Find l.c.m. of m,n and p\n",
+"m1 = m_inv*mul_fact;    // Clear the first fraction\n",
+"m2 = n_inv*mul_fact;    // Clear the second fraction\n",
+"m3 = p_inv*mul_fact;    // Clear the third fraction\n",
+"printf('\nThe required miller indices are : (%d %d %d) ', m1,m2,m3);\n",
+"\n",
+"// Result\n",
+"// The required miller indices are : (3 2 1)  "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.6: Meaning_of_hkl_notation_of_planes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.6: Page-378 (2008)\n",
+"clc; clear;\n",
+"// For first set (3, 2, 2)\n",
+"m = 3; n = 2; p = 2; // Coefficients of intercepts along three axes\n",
+"m_inv = 1/m;        // Reciprocate the first coefficient\n",
+"n_inv = 1/n;        // Reciprocate the second coefficient\n",
+"p_inv = 1/p;        // Reciprocate the third coefficient\n",
+"mul_fact = double(lcm(int32([m,n,p]))); // Find l.c.m. of m,n and p\n",
+"m1 = m_inv*mul_fact;    // Clear the first fraction\n",
+"m2 = n_inv*mul_fact;    // Clear the second fraction\n",
+"m3 = p_inv*mul_fact;    // Clear the third fraction\n",
+"printf('\nThe plane (%d %d %d) has intercepts %da, %db and %dc on the three axes.', m, n, p, m1, m2, m3);\n",
+"// For second set (1 1 1)\n",
+"m = 1; n = 1; p = 1; // Coefficients of intercepts along three axes\n",
+"m_inv = 1/m;        // Reciprocate the first coefficient\n",
+"n_inv = 1/n;        // Reciprocate the second coefficient\n",
+"p_inv = 1/p;        // Reciprocate the third coefficient\n",
+"mul_fact = double(lcm(int32([m,n,p]))); // Find l.c.m. of m,n and p\n",
+"m1 = m_inv*mul_fact;    // Clear the first fraction\n",
+"m2 = n_inv*mul_fact;    // Clear the second fraction\n",
+"m3 = p_inv*mul_fact;    // Clear the third fraction\n",
+"printf('\nThe plane (%d %d %d) has intercepts a, b and c on the three axes.', m, n, p);\n",
+"\n",
+"// Result\n",
+"// The plane (3 2 2) has intercepts 2a, 3b and 3c on the three axes.\n",
+"// The plane (1 1 1) has intercepts a, b and c on the three axes. "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.9: Lengths_of_intercepts_along_y_and_z_axis.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex7.9: Page-379 (2008)\n",
+"clc; clear;\n",
+"h = 2; k = 3; l = 1; // Miller indices of the set of planes\n",
+"p = 1/h;        // Reciprocate h\n",
+"q = 1/k;        // Reciprocate k\n",
+"r = 1/l;        // Reciprocate l\n",
+"lx = 1.2;    // Intercept cut by plane along x-axis, angstrom\n",
+"a = 1.2, b = 1.8, c = 2;    // Primitives of the crystal, angstrom\n",
+"mul_fact = double(lcm(int32([h, k, l]))); // Find l.c.m. of h, k and l\n",
+"pa = mul_fact*p*a;    \n",
+"qb = mul_fact*q*b;\n",
+"rc = mul_fact*r*c;\n",
+"ly = lx*qb/pa;    // Length of intercept along y-axis\n",
+"lz = lx*rc/pa;    // Length of intercept along z-axis\n",
+"printf('\nThe length of intercept along y-axis = %3.1f angstrom', ly);\n",
+"printf('\nThe length of intercept along z-axis = %3.1f angstrom', lz);\n",
+"\n",
+"// Result\n",
+"// The length of intercept along y-axis = 1.2 angstrom\n",
+"// The length of intercept along z-axis = 4.0 angstrom "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Engineering_Physics_by_D_C_Ghosh/8-Laser_and_Fibre_Optics.ipynb b/Engineering_Physics_by_D_C_Ghosh/8-Laser_and_Fibre_Optics.ipynb
new file mode 100644
index 0000000..3fab81d
--- /dev/null
+++ b/Engineering_Physics_by_D_C_Ghosh/8-Laser_and_Fibre_Optics.ipynb
@@ -0,0 +1,178 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 8: Laser and Fibre Optics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.1: Image_produced_by_laser_beam.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex8.1: Page-397 (2008)\n",
+"clc; clear;\n",
+"lambda = 6000e-008;     // Wavelength of the lase beam, cm\n",
+"P = 10e-003;    // Power of the laser beam, W\n",
+"theta = 1.5e-004;   // Angular spread of laser beam, rad\n",
+"f = 10;    // Focal length of the lens, cm\n",
+"r = f*theta;    // Radius of the image, cm\n",
+"rho = P/(%pi*r^2*1e+003);  // Power density of the image, kW/Sq.cm\n",
+"L_w = lambda/(theta/10);     // Coherence width, mm\n",
+"printf('\nThe radius of the image = %3.1e cm', r);\n",
+"printf('\nThe power density of the image = %3.1f kW/Sq.cm', rho);\n",
+"printf('\nThe coherence width = %d mm', L_w);\n",
+"// Result \n",
+"// The radius of the image = 1.5e-03 cm\n",
+"// The power density of the image = 1.4 kW/Sq.cm\n",
+"// The coherence width = 4 mm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.2: Pumping_energy_required_for_He_Ne_laser_transition.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex8.2: Page-398 (2008)\n",
+"clc; clear;\n",
+"lambda = 632.8e-009;     // Wavelength of the lase beam, cm\n",
+"E_2P = 15.2e-019;    // Energy of 2P level, J\n",
+"h = 6.626e-034;     // Planck's constant, Js\n",
+"c = 3e+008;     // Speed of light, m/s\n",
+"e = 1.6e-019;   // Energy equivalent of 1 eV, J/eV\n",
+"E_Pump = E_2P + h*c/lambda; // The required pumping energy, J\n",
+"printf('\nThe pumping energy required for He Ne laser transition = %5.2f eV', E_Pump/e);\n",
+"// Result \n",
+"// The pumping energy required for He Ne laser transition = 11.46 eV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.3: Wavelength_of_radiation_emitted_at_room_temperature.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex8.3: Page-398 (2008)\n",
+"clc; clear;\n",
+"h = 6.626e-034;     // Planck's constant, Js\n",
+"c = 3e+008;     // Speed of light, m/s\n",
+"T = 27+273;     // Room temperature, K\n",
+"k = 1.38e-023;  // Boltzmann constant, J/mol/K\n",
+"lambda = h*c/(k*T); // Wavelength of radiation mitted at room temperature, m\n",
+"printf('\nThe wavelength of radiation mitted at room temperature = %3.1e m', lambda);\n",
+"// Result \n",
+"// The wavelength of radiation mitted at room temperature = 4.8e-05 m"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.4: Refractive_index_of_the_cladding_in_an_optical_fibre.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex8.4: Page-398 (2008)\n",
+"clc; clear;\n",
+"NA = 0.5;   // Numerical aperture of the optical fibre\n",
+"n1 = 1.54;  // Refractive index of the core material\n",
+"n2 = sqrt(n1^2-NA^2);   // Refractive index of the cladding in an optical fibre\n",
+"printf('\nThe refractive index of the cladding in the optical fibre = %4.2f', n2);\n",
+"// Result \n",
+"// The refractive index of the cladding in the optical fibre = 1.46 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.5: Numerical_aperture_and_acceptance_angle_of_the_optical_fibre.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex8.5: Page-398 (2008)\n",
+"clc; clear;\n",
+"n1 = 1.51;  // Refractive index of the core material\n",
+"n2 = 1.47;   // Refractive index of the cladding \n",
+"NA = sqrt(n1^2-n2^2);   // Numerical aperture of the optical fibre\n",
+"n0 = 1;     // Refractive index of air\n",
+"theta_a = asin(NA/n0);  // Acceptance angle of the optical fibre, rad\n",
+"printf('\nThe numerical aperture of the optical fibre = %6.4f', NA);\n",
+"printf('\nThe acceptance angle of the optical fibre = %4.2f degrees', theta_a*180/3.14);\n",
+"// Result \n",
+"// The numerical aperture of the optical fibre = 0.3453\n",
+"// The acceptance angle of the optical fibre = 20.21 degrees "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Engineering_Physics_by_D_C_Ghosh/9-Nuclear_Physics.ipynb b/Engineering_Physics_by_D_C_Ghosh/9-Nuclear_Physics.ipynb
new file mode 100644
index 0000000..4f66f13
--- /dev/null
+++ b/Engineering_Physics_by_D_C_Ghosh/9-Nuclear_Physics.ipynb
@@ -0,0 +1,691 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 9: Nuclear Physics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.1_1: Binding_energy_per_nucleon_for_Ni.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.1.1:Page-411 (2008)\n",
+"clc; clear;\n",
+"u = 931.508;    // Energy equivalent of 1 amu, MeV\n",
+"Z = 28;    // Atomic number of ni-64\n",
+"A = 64;    // Mass number of Ni-64\n",
+"m_p = 1.007825;     // Mass of a proton, u\n",
+"m_n = 1.008665;    // Mass of a neutron, u\n",
+"M_Ni = 63.9280;    // Atomic mass of Ni-64 nucleus, u\n",
+"delta_m = Z*m_p + (A-Z)*m_n - M_Ni;    // Mass difference, u\n",
+"BE = delta_m*u;    // Binding energy of Ni-64 nucleus, MeV\n",
+"BE_bar = BE/A;    // Binding energy per nucleon of Ni-64 nucleus, MeV\n",
+"printf('\nThe binding energy per nucleon for Ni-64 nucleus = %4.2f MeV/nucleon', BE_bar);\n",
+"// Result \n",
+"// The binding energy per nucleon for Ni-64 nucleus = 8.78 MeV/nucleon "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.1_2: Binding_energy_per_nucleon_for_deutron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.1.2:Page-411 (2008)\n",
+"clc; clear;\n",
+"e = 1.6e-013;    // Energy equivalent of 1 MeV, J\n",
+"m_p = 1.672e-027;     // Mass of a proton, kg\n",
+"m_n = 1.675e-027;    // Mass of a neutron, kg\n",
+"M_D = 3.343e-027;    // Mass of a deutron, kg\n",
+"c = 3.00e+008;    // Speed of light in vacuum, m/s\n",
+"delta_m = m_p + m_n - M_D;    // Mass defect, kg\n",
+"E_B = delta_m*c^2/e;    // Binding energy for the deutron, MeV\n",
+"BE_bar = E_B/2;    // Binding energy per nucleon for the deutron, MeV\n",
+"printf('\nThe binding energy per nucleon for the deutron = %5.3f MeV/nucleon', BE_bar);\n",
+"// Result \n",
+"// The binding energy per nucleon for the deutron = 1.125 MeV/nucleon "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.1_3: Packing_fraction_and_binding_energy_per_nucleon_for_oxygen.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.1.3:Page-411 (2008)\n",
+"clc; clear;\n",
+"u = 931.508;    // Energy equivalent of 1 amu, MeV\n",
+"Z = 8;    // Atomic number of O-16\n",
+"A = 16;    // Mass number of O-16\n",
+"m_p = 1.008142;     // Mass of a proton, u\n",
+"m_n = 1.008982;    // Mass of a neutron, u\n",
+"M_O = 15.994915;    // Atomic mass of O-16 nucleus, u\n",
+"delta_m = Z*m_p + (A-Z)*m_n - M_O;    // Mass difference, u\n",
+"BE = delta_m*u;    // Binding energy of O-16 nucleus, MeV\n",
+"BE_bar = BE/A;    // Binding energy per nucleon of O-16 nucleus, MeV\n",
+"delta_m = abs(M_O - A);    // Mass difference, u\n",
+"PF = delta_m/A;    // Packing fraction for O-16 nucleus, u\n",
+"printf('\nThe binding energy per nucleon for O-16 nucleus = %4.2f MeV/nucleon', BE_bar);\n",
+"printf('\nThe packing fraction for O-16 nucleus = %5.3e u', PF);\n",
+"// Result \n",
+"// The binding energy per nucleon for O-16 nucleus = 8.27 MeV/nucleon\n",
+"// The packing fraction for O-16 nucleus = 3.178e-004 u "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.1_4: Atomic_mass_of_neon.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.1.4: Page-411 (2008)\n",
+"clc; clear;\n",
+"u = 931.508;    // Energy equivalent of 1 amu, MeV\n",
+"Z = 10;    // Atomic number of Ne-20\n",
+"A = 20;    // Mass number of Ne-0\n",
+"m_p = 1.007825;     // Mass of a proton, u\n",
+"m_n = 1.008665;    // Mass of a neutron, u\n",
+"BE = 160.64;    // Binding energy of Ne-20 nucleus, MeV\n",
+"M = Z*m_p + (A-Z)*m_n + Z*0.51/u - BE/u;    // Atomic mass of Ne-20 nucleus, u\n",
+"printf('\nThe atomic mass of Ne = %7.4f a.m.u', M);\n",
+"// Result \n",
+"// The atomic mass of Ne = 19.9979 a.m.u "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_11: Q_value_of_nuclear_reaction.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.11: Page-418(2008)\n",
+"clc; clear;\n",
+"u = 931.5;    // Energy equivalent of 1 amu, MeV\n",
+"m_x = 4.002603;    // Mass of projectile (alpha-particle), u\n",
+"m_y = 1.007825;    // Mass of emitted particle (proton), u\n",
+"M_X = 14.0031;     // Mass of target nucleus (N-14), u\n",
+"M_Y = 16.9994;    // Mass of daughter nucleus (O-16), u\n",
+"Q = ((m_x + M_X) - (m_y + M_Y))*u;    // Q-value of the reaction, MeV\n",
+"printf('\nThe Q-value of the nuclear reaction = %5.3f MeV', Q);\n",
+"// Result \n",
+"// The Q-value of the nuclear reaction = -1.418 MeV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_12: Threshold_energy_for_the_reactions.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.12: Page-418(2008)\n",
+"clc; clear;\n",
+"u = 931.5;    // Energy equivalent of 1 amu, MeV\n",
+"// First reaction\n",
+"m_x = 1.007825;    // Mass of projectile (proton), u\n",
+"m_y = 2.014102;    // Mass of emitted particle (deutron), u\n",
+"M_X = 208.980394;     // Mass of target nucleus (Bi-209), u\n",
+"M_Y = 207.979731;    // Mass of daughter nucleus (Bi-208), u\n",
+"Q = ((m_x + M_X) - (m_y + M_Y))*u;    // Q-value of the reaction, MeV\n",
+"Ex_threshold = -Q*(m_x + M_X)/M_X;    // The smallest value of the projectile energy, MeV\n",
+"printf('\nThe threshhold energy of the reaction Bi(209,83) + p --> Bi(208,83) + d = %4.2f MeV', Ex_threshold);\n",
+"// Second reaction\n",
+"m_x = 4.002603;    // Mass of projectile (alpha-particle), u\n",
+"m_y = 1.007825;    // Mass of emitted particle (proton), u\n",
+"M_X = 27.98210;     // Mass of target nucleus (Al-27), u\n",
+"M_Y = 30.973765;    // Mass of daughter nucleus (P-31), u\n",
+"Q = ((m_x + M_X) - (m_y + M_Y))*u;    // Q-value of the reaction, MeV\n",
+"Ex_threshold = -Q*(m_x + M_X)/M_X;    // The smallest value of the projectile energy, MeV\n",
+"printf('\nThe threshhold energy of the reaction Al(27,13) + He --> P(31,15) + p = %4.2f MeV', Ex_threshold);\n",
+"// Result \n",
+"// The threshhold energy of the reaction Bi(209,83) + p --> Bi(208,83) + d = 5.25 MeV\n",
+"// The threshhold energy of the reaction Al(27,13) + He --> P(31,15) + p = -3.31 MeV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_13: Finding_unknown_particles_in_the_nuclear_reactions.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.13: Page-418(2008)\n",
+"clc; clear;\n",
+"function p = Find(Z, A)\n",
+"    if Z == 2 & A == 4 then\n",
+"        p = 'alpha';\n",
+"    end\n",
+"    if Z == -1 & A == 0 then\n",
+"        p = 'beta-';\n",
+"    end\n",
+"    if  Z == 1 & A == 0 then\n",
+"        p = 'beta+';\n",
+"    end\n",
+"endfunction   \n",
+"R1 = cell(4,3);\n",
+"R2 = cell(4,3);\n",
+"// Enter data for first cell (Reaction)\n",
+"R1(1,1).entries = 'Li'; // Element\n",
+"R1(1,2).entries = 3;   // Atomic number\n",
+"R1(1,3).entries = 6;    // Mass number\n",
+"R1(2,1).entries = 'd';\n",
+"R1(2,2).entries = 1;\n",
+"R1(2,3).entries = 2;\n",
+"R1(3,1).entries = 'X';\n",
+"R1(3,2).entries = 0;\n",
+"R1(3,3).entries = 0;\n",
+"R1(4,1).entries = 'He';\n",
+"R1(4,2).entries = 2;\n",
+"R1(4,3).entries = 4;\n",
+"// Enter data for second cell (Reaction)\n",
+"R2(1,1).entries = 'Te';\n",
+"R2(1,2).entries = 52;\n",
+"R2(1,3).entries = 122;\n",
+"R2(2,1).entries = 'X';\n",
+"R2(2,2).entries = 0;\n",
+"R2(2,3).entries = 0;\n",
+"R2(3,1).entries = 'I';\n",
+"R2(3,2).entries = 53;\n",
+"R2(3,3).entries = 124;\n",
+"R2(4,1).entries = 'd';\n",
+"R2(4,2).entries = 1;\n",
+"R2(4,3).entries = 2;\n",
+"R1(3,2).entries = R1(1,2).entries+R1(2,2).entries-R1(4,2).entries\n",
+"R1(3,3).entries = R1(1,3).entries+R1(2,3).entries-R1(4,3).entries\n",
+"particle = Find(R1(3,2).entries, R1(3,3).entries);    // Find the unknown particle\n",
+"printf('\nFor the reaction\n')\n",
+"            printf('\t%s(%d) + %s(%d) --> %s + %s(%d)\n X must be an %s particle', R1(1,1).entries, R1(1,3).entries, R1(2,1).entries, R1(2,3).entries, R1(3,1).entries, R1(4,1).entries, R1(4,3).entries, particle);\n",
+"R2(2,2).entries = R2(3,2).entries+R2(4,2).entries-R2(1,2).entries\n",
+"R2(2,3).entries = R2(3,3).entries+R2(4,3).entries-R2(1,3).entries\n",
+"particle = Find(R2(2,2).entries, R2(2,3).entries);    // Find the unknown particle\n",
+"printf('\n\nFor the reaction\n')\n",
+"            printf('\t%s(%d) + %s --> %s(%d)+%s(%d)\n X must be an %s particle', R2(1,1).entries, R2(1,3).entries, R2(2,1).entries, R2(3,1).entries, R2(3,3).entries, R2(4,1).entries, R2(4,3).entries, particle);\n",
+"            \n",
+"// Result\n",
+"// For the reaction\n",
+"//	Li(6) + d(2) --> X + He(4)\n",
+"//  X must be an alpha particle\n",
+"// For the reaction\n",
+"// 	Te(122) + X --> I(124)+d(2)\n",
+"//  X must be an alpha particle "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_14: Comptom_scattering.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.14: Page-419(2008)\n",
+"clc; clear;\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"c = 3e+008;    // Speed of light, m/s\n",
+"lambda = 10e-012;    // Wavelength of incident X-rays, m\n",
+"lambda_c = 2.426e-012;    // Compton wavelength for the electron, m\n",
+"phi = 45;    // Angle of scattering of X-rays, degree\n",
+"lambda_prime = lambda + lambda_c*(1 - cosd(phi));    // Wavelength of scattered X-rays, m\n",
+"// For maximum wavelength\n",
+"phi = 180;    // Angle for maximum scattering, degree\n",
+"lambda_prime_max = lambda + lambda_c*(1 - cosd(phi)) ;    // Maximum wavelength present in the scattered X-rays, m\n",
+"KE_max = h*c*(1/lambda-1/lambda_prime_max);    // Maximum kinetic energy of the recoil electrons, J\n",
+"printf('\nThe wavelength of scattered X-rays = %5.2e m', lambda_prime);\n",
+"printf('\nThe maximum wavelength present in the scattered X-rays = %6.3f pm', lambda_prime_max/1e-012);\n",
+"printf('\nThe maximum kinetic energy of the recoil electrons = %5.3e J', KE_max);\n",
+"// Result\n",
+"// The wavelength of scattered X-rays = 1.07e-011 m\n",
+"// The maximum wavelength present in the scattered X-rays = 14.852 pm\n",
+"// The maximum kinetic energy of the recoil electrons = 6.498e-015 J "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_16: Miller_indices_for_the_lattice_planes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.16: Page-420(2008)\n",
+"clc; clear;\n",
+"m = 3; n = 3; p = 2; // Coefficients of intercepts along three axes\n",
+"m_inv = 1/m;        // Reciprocate the first coefficient\n",
+"n_inv = 1/n;        // Reciprocate the second coefficient\n",
+"p_inv = 1/p;        // Reciprocate the third coefficient\n",
+"mul_fact = double(lcm(int32([m,n,p]))); // Find l.c.m. of m,n and p\n",
+"m1 = m_inv*mul_fact;    // Clear the first fraction\n",
+"m2 = n_inv*mul_fact;    // Clear the second fraction\n",
+"m3 = p_inv*mul_fact;    // Clear the third fraction\n",
+"printf('\nThe miller indices for planes with set of intercepts (%da, %db, %dc) are (%d %d %d) ', m, n, p, m1, m2, m3);\n",
+"m = 1; n = 2; p = %inf; // Coefficients of intercepts along three axes\n",
+"m_inv = 1/m;        // Reciprocate the first coefficient\n",
+"n_inv = 1/n;        // Reciprocate the second coefficient\n",
+"p_inv = 1/p;        // Reciprocate the third coefficient\n",
+"mul_fact = double(lcm(int32([m,n]))); // Find l.c.m. of m,n and p\n",
+"m1 = m_inv*mul_fact;    // Clear the first fraction\n",
+"m2 = n_inv*mul_fact;    // Clear the second fraction\n",
+"m3 = p_inv*mul_fact;    // Clear the third fraction\n",
+"printf('\nThe miller indices for planes with set of intercepts (%da, %db, %dc) are (%d %d %d) ', m, n, p, m1, m2, m3);\n",
+"// Result\n",
+"// The miller indices for planes with set of intercepts (3a, 3b, 2c) are (2 2 3) \n",
+"// The miller indices for planes with set of intercepts (1a, 2b, Infc) are (2 1 0)  "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_19: Glancing_angles_for_the_second_and_third_order_reflections.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.19: Page-421(2008)\n",
+"clc; clear;\n",
+"d = 1;    // For simplicity assume interplanar spacing to be unity, m\n",
+"theta = 15;    // Glancing angle for first order, degree\n",
+"n = 1;    // Order of reflection\n",
+"// From Bragg's law, 2*d*sind(theta) = n*lambda, solving for lambda\n",
+"lambda = 2*d*sind(theta)/n;    // Wavelength of incident X-ray, angstrom\n",
+"// For second order reflection\n",
+"n = 2\n",
+"theta = asind(n*lambda/(2*d));    // Glancing angle for second order reflection, degree\n",
+"printf('\nThe glancing angle for the second order reflection = %4.1f degree', theta);\n",
+"// For third order reflection\n",
+"n = 3;\n",
+"theta = asind(n*lambda/(2*d));    // Glancing angle for third order reflection, degree\n",
+"printf('\nThe glancing angle for the third order reflection = %4.1f degree', theta);\n",
+"// Result\n",
+"// The glancing angle for the second order reflection = 31.2 degree\n",
+"// The glancing angle for the third order reflection = 50.9 degree "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_1: Average_number_of_photons_pe_cubic_metre_in_a_monochromatic_beam.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.1: Page-414 (2008)\n",
+"clc; clear;\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"c = 3.00e+008;    // Speed of light in vacuum, m/s\n",
+"I = 1e+004;    // Intensity of monochromatic beam, W/Sq.m\n",
+"nu = 1e+004;    // Frequency of monochromatic beam, Hz\n",
+"n = I/(h*nu*c);    // Average number of photons per cubic metre, photons/metre-cube\n",
+"printf('\nThe average number of photons in the monochromatic beam of radiation = %4.2e photons/metre-cube', n);\n",
+"// Result \n",
+"// The average number of photons in the monochromatic beam of radiation = 5.03e+024 photons/metre-cube "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_2: Average_number_of_photons_pe_cubic_metre_in_a_monochromatic_beam.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.2: : Page-414 (2008)\n",
+"clc; clear;\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"c = 3.00e+008;    // Speed of light in vacuum, m/s\n",
+"I = 1e+004;    // Intensity of monochromatic beam, W/Sq.m\n",
+"nu = 1e+004;    // Frequency of monochromatic beam, Hz\n",
+"n = I/(h*nu*c);    // Average number of photons per cubic metre, photons/metre-cube\n",
+"printf('\nThe average number of photons in the monochromatic beam of radiation = %4.2e photons/metre-cube', n);\n",
+"// Result \n",
+"// The average number of photons in the monochromatic beam of radiation = 5.03e+024 photons/metre-cube "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_3: Photoelectric_effect_with_silver.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.3: Page-414 (2008)\n",
+"clc; clear;\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"c = 3.00e+008;    // Speed of light in vacuum, m/s\n",
+"e = 1.6e-019;    // Energy equivalent of 1 eV, J\n",
+"m_e = 9.1e-031;    // Rest mass of an electron, kg\n",
+"lambda0 = 2762e-010;    // Thereshold wavelength of silver, m\n",
+"lambda = 2000e-010;    // Wavelength of ultraviolet rays, m\n",
+"E_max = h*c*(1/lambda - 1/lambda0);    // Maximum kinetic energy of the ejected electrons from Einstein's photoelectric equation, J\n",
+"// As E_max = 1/2*m_e*v^2, solving for v\n",
+"v_max = sqrt(2*E_max/m_e);    // Maximum velocity of the photoelectrons, m/s\n",
+"V0 = E_max/e;    // Stopping potential for the electrons, V\n",
+"printf('\nThe maximum kinetic energy of the ejected electrons = %5.3e J', E_max);\n",
+"printf('\nThe maximum velocity of the photoelectrons = %4.2e m/s', v_max);\n",
+"printf('\nThe stopping potential for the electrons = %5.3f V', V0);\n",
+"// Result \n",
+"// The maximum kinetic energy of the ejected electrons = 2.744e-019 J\n",
+"// The maximum velocity of the photoelectrons = 7.77e+005 m/s\n",
+"// The stopping potential for the electrons = 1.715 V "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_4: Work_function_of_the_metallic_surface.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.4: Page-415 (2008)\n",
+"clc; clear;\n",
+"lambda1 = 3333e-010;    // First wavelength of the incident light, m\n",
+"lambda2 = 2400e-010;    // Second wavelength of the incident light, m\n",
+"c = 3e+008;    // Speed of light in free space, m/s\n",
+"e = 1.6e-019;    // Energy equivalent of 1 eV, J\n",
+"E1 = 0.6;    // Kinetic energy of the emitted photoelectrons for the first wavelength, eV\n",
+"E2 = 2.04;     // Kinetic energy of the emitted photoelectrons for the second wavelength, eV\n",
+"h = (E2 - E1)*lambda1*lambda2*e/(c*(lambda1 - lambda2));    // Planck's constant, Js\n",
+"W0 = (E2*lambda2 - E1*lambda1)/(lambda1 - lambda2);    // Work function of the metal, eV\n",
+"printf('\nThe value of Planck constant = %3.1e Js', h);\n",
+"printf('\nThe work function of the metal = %3.1f eV', W0);\n",
+"// Result \n",
+"// The value of Planck constant = 6.6e-034 Js\n",
+"// The work function of the metal = 3.1 eV "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_5: Wavelength_of_the_scattered_photon.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.5: Page-415 (2008)\n",
+"clc; clear;\n",
+"c = 3e+008;    // Speed of light in free space, m/s\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"m_e = 9.11e-031;    // Rest mass of an electron, kg\n",
+"lambda = 0.3;    // Wavelength of incident X-ray photon, angstrom\n",
+"phi = 45;    // The angle of scattering, degrees\n",
+"lambda_prime = lambda + h/(m_e*c*1e-010)*(1-cosd(phi));    // The wavelength of the scattered photon, angstrom\n",
+"printf('\nThe wavelength of the scattered photon = %6.4f angstrom', lambda_prime);\n",
+"// Result \n",
+"// The wavelength of the scattered photon = 0.3071 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_6: de_Broglie_wavelength_of_the_valence_electron_in_metallic_sodium.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.6: Page-416 (2008)\n",
+"clc; clear;\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"m_e = 9.11e-031;    // Rest mass of an electron, kg\n",
+"e = 1.6e-019;    // Energy equivalent of 1 eV, J\n",
+"K = 3*e;    // Kinetic energy of the electron in metllic sodium, J\n",
+"lambda = h/sqrt(2*m_e*K)/1e-010;    // de Broglie wavelength of the valence electron, angstrom\n",
+"printf('\nThe de-Broglie wavelength of the valence electron = %3.1f angstrom', lambda);\n",
+"// Result \n",
+"// The de-Broglie wavelength of the valence electron = 7.1 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_7: de_Broglie_wavelength_of_a_moving_electron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.7: Page-416 (2008)\n",
+"clc; clear;\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"m = 9.11e-031;    // Rest mass of an electron, kg\n",
+"c = 3e+008;    // Speed of light in vacuum, m/s\n",
+"bita = 3/5;    // Boost parameter\n",
+"v = 3/5*c;    // Spped of the electron, m/s\n",
+"lambda = h/(m*v)*sqrt(1-bita^2);    // de Broglie wavelength of the electron, m\n",
+"printf('\nThe de-Broglie wavelength of the moving electron = %6.4f angstrom', lambda/1e-010);\n",
+"// Result \n",
+"// The de-Broglie wavelength of the moving electron = 0.0323 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_8: Uncertainty_in_energy_and_frequency_of_emitted_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.8: Page-416 (2008)\n",
+"clc; clear;\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"h_bar = h/(2*%pi);    // Reduced Planck's constant, Js\n",
+"delta_t = 1e-008;    // Time during which the radiation is emitted, s\n",
+"delta_E = h_bar/delta_t;    // Minimum uncertainty in energy of emitted light, J\n",
+"// As delta_E = h*delta_nu from Planck's quantum theory, solving for delta_nu\n",
+"delta_nu = delta_E/h;    // Minimum uncertainty in frequency of emitted light, Hz\n",
+"printf('\nThe minimum uncertainty in energy of emitted light = %5.3e J', delta_E);\n",
+"printf('\nThe minimum uncertainty in frequency of emitted light = %4.2e Hz', delta_nu);\n",
+"// Result \n",
+"// The minimum uncertainty in energy of emitted ligh = 1.055e-026 J\n",
+"// The minimum uncertainty in frequency of emitted ligh = 1.59e+007 Hz "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2_9: Shortest_wavelength_present_in_the_radiation_from_an_X_ray_machine.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex9.2.9: Page-417 (2008)\n",
+"clc; clear;\n",
+"h = 6.63e-034;    // Planck's constant, Js\n",
+"c = 3e+008;    // Speed of light in free space, m/s\n",
+"e = 1.6e-019;    // Energy equivalent of 1 eV, J\n",
+"V = 50000;    // Accelerating potential, V\n",
+"lambda_min = h*c/(e*V);    // The shortest wavelength present in the radiation from an X-ray machine, m\n",
+"printf('\nThe shortest wavelength present in the radiation from an X-ray machine = %6.4f nm', lambda_min/1e-009);\n",
+"// Result \n",
+"// The shortest wavelength present in the radiation from an X-ray machine = 0.0249 nm "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}