Merge pull request #1 from prashantsinalkar/masterHEADmaster

Initial commit

1 files changed, 1494 insertions, 0 deletions

diff --git a/Engineering_Physics_by_V_Yadav/3-Diffraction.ipynb b/Engineering_Physics_by_V_Yadav/3-Diffraction.ipynb
new file mode 100644
index 0000000..4eb1e2e
--- /dev/null
+++ b/Engineering_Physics_by_V_Yadav/3-Diffraction.ipynb
@@ -0,0 +1,1494 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 3: Diffraction"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.10: Slit_width_in_Fraunhoffer_single_slit_experiment.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.10:: Page-3.24 (2009)\n",
+"clc; clear;\n",
+"f = 250;        // Focal length of the lens, cm\n",
+"x = 0.8;        // Half width of central maxima, cm\n",
+"lambda = 5500e-008;     // Wavelength of light used, cm\n",
+"// As x = f*lambda/a, solving for a\n",
+"a = f*lambda/x;     // Slit width in Fraunhofer single slit experiment\n",
+"\n",
+"printf('\nThe slit width = %5.3f cm', a);\n",
+"\n",
+"// Result \n",
+"// The slit width = 0.017 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.11: Half_angular_width_of_central_maxima.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.11:: Page-3.25 (2009)\n",
+"clc; clear;\n",
+"lambda = 5500e-008;     // Wavelength of light used, cm\n",
+"a = 8.5e-005;    // Width of the slit, cm\n",
+"n = 1;      // Order of diffraction\n",
+"// For a single slit Fraunhofer diffraction, a*sind(theta) = n*lambda, solving for theta\n",
+"theta = asind(n*lambda/a);  // Half angular width at central maximum in Fraunhoffer diffraction, degrees\n",
+"\n",
+"printf('\nThe half angular width at central maximum in Fraunhoffer diffraction = %4.1f degrees', theta);\n",
+"\n",
+"// Result \n",
+"// The half angular width at central maximum in Fraunhoffer diffraction = 40.3 degrees "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.12: Wavelength_of_light_used_in_Fraunhoffer_diffraction_due_to_single_slit.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.12:: Page-3.25 (2009)\n",
+"clc; clear;\n",
+"a = 0.04;       // Slit width, cm\n",
+"x = 0.5;        // Half width of central maximum, cm\n",
+"f = 300;        // Focal length of the lens, cm\n",
+"// As x = lambda*f/a, solving for lambda\n",
+"lambda = a*x/f;     // Wavelength of light used in Fraunhoffer diffraction due to single slit, cm\n",
+"\n",
+"printf('\nThe wavelength of light used in Fraunhoffer diffraction due to a single slit = %4d angstrom', lambda/1e-008);\n",
+"\n",
+"// Result \n",
+"// The wavelength of light used in Fraunhoffer diffraction due to a single slit = 6666 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.13: Width_of_central_maxima_from_position_of_first_secondary_minima.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.13:: Page-3.25 (2009)\n",
+"clc; clear;\n",
+"a = 0.045;       // Slit width, cm\n",
+"lambda = 5500e-008;     // Wavelength of light used, cm\n",
+"f = 250;        // Focal length of the lens, cm\n",
+"x = lambda*f/a;     // Position of central maxima, cm\n",
+"\n",
+"printf('\nThe position of central maxima = %5.3f cm', x);\n",
+"printf('\nThe width of central maxima from first minima = %5.3f cm', 2*x);\n",
+"\n",
+"// Result \n",
+"// The position of central maxima = 0.306 cm\n",
+"// The width of central maxima from first minima = 0.611 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.14: Wavelength_of_monochromatic_light_used_in_illuminating_a_slit.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.14:: Page-3.26 (2009)\n",
+"clc; clear;\n",
+"a = 0.025;       // Slit width, cm\n",
+"n = 2;          // Order of diffraction\n",
+"f = 400;        // Focal length of the lens, cm\n",
+"x = 2.1;        // Position of central maxima, cm\n",
+"// As theta = n*lambda/a and theta = x/f, solving for lambda\n",
+"lambda = x*a/(n*f);     // 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 = 6562 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.15: Distance_between_second_dark_and_next_bright_fringe_on_the_axes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.15:: Page-3.26 (2009)\n",
+"clc; clear;\n",
+"a = 0.25;       // Slit width, cm\n",
+"lambda = 5890e-008;     // Wavelength of light, cm\n",
+"f = 80;         // Focal length of the lens, cm\n",
+"n = 2;          // Order of diffraction\n",
+"// As for minima, theta = n*lambda/a and theta = x/f, solving for x\n",
+"x2 = 2*lambda*f/a;        // Position of 2nd dark fringe, cm\n",
+"// As for maxima, theta = (2*n+1)*lambda/(2*a) and theta = x/f, solving for x\n",
+"x2_prime = 5*lambda*f/(2*a);        // Position of 2nd bright fringe, cm\n",
+"delta_x = x2_prime-x2;      // Distance between 2nd dark and next bright, cm\n",
+"printf('\nThe distance between 2nd dark and next bright fringe = %4.2e cm', delta_x);\n",
+"\n",
+"// Result \n",
+"// The distance between 2nd dark and next bright fringe = 9.42e-003 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.16: Width_of_the_slit_from_first_order_diffractio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.16:: Page-3.27 (2009)\n",
+"clc; clear;\n",
+"lambda = 5500e-008;     // Wavelength of light used, cm\n",
+"x = 3.9e-001;       // Half width of central maximum, cm\n",
+"f = 220;        // Focal length of the lens, cm\n",
+"n = 1;      // Order for first order diffraction\n",
+"// As a*sin(theta) = n*lambda, a*theta = n*lambda\n",
+"// As theta = lambda/a and theta = x/f, solving for a\n",
+"a = lambda*f/x;     // Half angular width at central maximum, cm\n",
+"\n",
+"printf('\nThe width of the slit = %3.1e cm', a);\n",
+"\n",
+"// Result \n",
+"// The width of the slit = 3.1e-002 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.18: Fraunhoffer_diffraction_due_to_double_slits.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.18:: Page-3.30 (2009)\n",
+"clc; clear;\n",
+"a = 0.019e-003;     // Width of each slit, m\n",
+"b = 2.0e-004;       // Width of opacity between two slits, m\n",
+"lambda = 5000e-010; // Wavelengh of light used, m\n",
+"D = 0.6;        // Distance between slit and the screen, m\n",
+"// As angular separation, theta = x/D = lambda/(a+b), solving for x\n",
+"x = D*lambda/(a+b);     // Fringe spacing on the screen, m\n",
+"// As half angular separation, theta1 = x1/D = lambda/(2*(a+b)), solving for x1\n",
+"x1 = D*lambda/(2*(a+b));       // Distance between central maxima and first minima, m\n",
+"\n",
+"printf('\nThe fringe spacing on the screen = %4.2f mm', x/1e-003);\n",
+"printf('\nThe distance between central maxima and first minima = %4.2f mm', x1/1e-003);\n",
+"\n",
+"// Result \n",
+"// The fringe spacing on the screen = 1.37 mm\n",
+"// The distance between central maxima and first minima = 0.68 mm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.19: Fringe_separation_in_Fraunhoffer_double_slit_diffraction_pattern.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.19:: Page-3.31 (2009)\n",
+"clc; clear;\n",
+"f = 150;    // Distance between screen and slit, cm\n",
+"a = 0.005;  // Slit width, cm\n",
+"b = 0.06;   // Distance between slits, cm\n",
+"lambda = 5500e-008;     // Wavelength of light used, cm\n",
+"// As half angular separation, theta1 = x1/f = lambda/(2*(a+b)), solving for x1\n",
+"x1 = f*lambda/(2*(a+b));       // Distance between central maxima and first minima, cm\n",
+"delta_theta = lambda/(2*(a+b)); // Angular separation between two consecutive minima, radians\n",
+"printf('\nThe distance between central maxima and first minima = %4.2e cm', x1);\n",
+"printf('\nThe angular separation between two consecutive minima = %3.1e radians', delta_theta);\n",
+"\n",
+"// Result \n",
+"// The distance between central maxima and first minima = 6.35e-002 cm\n",
+"// The angular separation between two consecutive minima = 4.2e-004 radians "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.1: Position_of_the_screen_so_that_light_is_focused_on_the_brightest_spot.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.1:: Page-3.9 (2009)\n",
+"clc; clear;\n",
+"lambda = 5890e-008;  // Wavelength of light used, cm\n",
+"r1 = 0.2;   // Radius of first ring of zone plate, cm\n",
+"n = 1;  // Order of zone plate\n",
+"f1 = r1^2/(n*lambda);   // Position of the screen so that light is focused on the brightest spot, cm\n",
+" \n",
+"printf('\nThe position of the screen so that light is focused on the brightest spot = %3.1e cm', lambda);\n",
+"\n",
+"// Result \n",
+"// The position of the screen so that light is focused on the brightest spot = 5.9e-005 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.20: Positions_of_first_secondary_maxima_and_minima_in_double_slit_diffraction.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.20:: Page-3.32 (2009)\n",
+"clc; clear;\n",
+"f = 120;    // Distance between screen and slit, cm\n",
+"a = 0.019;  // Slit width, cm\n",
+"b = 0.041;   // Distance between slits, cm\n",
+"lambda = 6500e-008;     // Wavelength of light used, cm\n",
+"// As theta1 = x1/f = lambda/(2*(a+b)), solving for x1\n",
+"x1 = f*lambda/(2*(a+b));       // Position of first secondary minima, cm\n",
+"// As theta2 = x2/f = lambda/(a+b), solving for x2\n",
+"x2 = f*lambda/(a+b);       // Position of first secondary maxima, cm\n",
+"\n",
+"printf('\nThe position of first secondary minima = %5.3f cm', x1);\n",
+"printf('\nThe position of first secondary maxima = %4.2f cm', x2);\n",
+"\n",
+"// Result \n",
+"// The position of first secondary minima = 0.065 cm\n",
+"// The position of first secondary maxima = 0.13 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.21: Missing_orders_of_spectra_in_Fraunhoffer_double_slit_diffraction.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.21:: Page-3.34 (2009)\n",
+"clc; clear;\n",
+"a = 0.2;  // Slit width, mm\n",
+"b = 0.8;   // Distance between slits, mm\n",
+"p = [1 2 3 4];      // Orders of pth diffraction maxima\n",
+"// As diffraction of pth diffraction maxima, a*sin(theta)=p*lambda --- (i)\n",
+"// and that of nth diffraction maxima, (a+b)*sin(theta)=n*lambda --- (ii)\n",
+"// Dividing (ii) by (i), we have\n",
+"// (a+b)/a = n/p, solving for n\n",
+"n = (a+b)/a*p;  // Orders of nth diffraction maxima\n",
+"\n",
+"printf('\nThe missing orders of spectra in diffraction maxima, n = %d, %d, %d, %d,...', n(1), n(2), n(3), n(4));\n",
+"\n",
+"\n",
+"// Result \n",
+"// The missing orders of spectra in diffraction maxima, n = 5, 10, 15, 20,... "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.22: Angles_of_diffraction_for_the_principal_maxima_for_two_lines_of_sodium.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.22:: Page-3.45 (2009)\n",
+"clc; clear;\n",
+"lambda1 = 5890e-008;    // Wavelength of D1 line of Na, cm\n",
+"lambda2 = 5896e-008;    // Wavelength of D2 line of Na, cm\n",
+"N = 3000/0.5;           // No. of lines per cm of grating, lines/cm\n",
+"a_plus_b = 1/N;         // Grating element, cm\n",
+"n = 1;      // Order of diffraction for principal maxima\n",
+"// As (a+b)*sin(theta1) = n*lambda, solving for theta1\n",
+"theta1 = asind(n*lambda1/(a_plus_b)); // Angle of diffraction for the principal maxima of D1 line, degrees\n",
+"theta2 = asind(n*lambda2/(a_plus_b)); // Angle of diffraction for the principal maxima of D2 line, degrees\n",
+"printf('\nThe angle of diffraction for the principal maxima of D1 line = %5.2f degrees', theta1);\n",
+"printf('\nThe angle of diffraction for the principal maxima of D2 line = %5.2f degrees', theta2);\n",
+"\n",
+"// Result \n",
+"// The angle of diffraction for the principal maxima of D1 line = 20.70 degrees\n",
+"// The angle of diffraction for the principal maxima of D2 line = 20.72 degrees "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.23: Highest_order_spectrum_which_can_be_seen_in_monochromatic_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.23:: Page-3.45 (2009)\n",
+"clc; clear;\n",
+"lambda = 5500e-008;    // Wavelength of light used, cm\n",
+"N = 15000;           // No. of lines per inch of grating, lines/inch\n",
+"a_plus_b = 2.54/N;         // Grating element, cm\n",
+"n = 1;      // Order of diffraction for principal maxima\n",
+"// As (a+b)*sin(theta_n) = n*lambda and for maximum possible order of spectra sin(theta_n) = 1\n",
+"// So (a+b) = n*lambda, solving for n\n",
+"n = (a_plus_b)/lambda;   // The highest order spectrum which can be seen in monochromatic light\n",
+"\n",
+"printf('\nThe highest order spectrum which can be seen in monochromatic light = %d', n);\n",
+"\n",
+"// Result \n",
+"// The highest order spectrum which can be seen in monochromatic light = 3  "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.24: Angle_of_separation_in_second_order_of_diffraction_spectrum.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.24: : Page-3.46 (2009)\n",
+"clc; clear;\n",
+"lambda1 = 5890e-008;    // Wavelength of D1 line, cm\n",
+"lambda2 = 5896e-008;    // Wavelength of D2 line, cm\n",
+"N = 15000;           // No. of lines per inch of grating, lines/inch\n",
+"a_plus_b = 2.54/N;         // Grating element, cm\n",
+"n = 2;      // Order of diffraction for secondary maxima\n",
+"// As (a+b)*sin(theta_n) = n*lambda, solving for theta1 and theta2\n",
+"theta1 = asind(n*lambda1/a_plus_b);     // Direction of secondary maxima with lambda1, degrees\n",
+"theta2 = asind(n*lambda2/a_plus_b);     // Direction of secondary maxima with lambda2, degrees\n",
+"\n",
+"printf('\nThe angle of separation in second order diffraction spectrum = %3.1f degrees', theta2-theta1);\n",
+"\n",
+"// Result \n",
+"// The angle of separation in second order diffraction spectrum = 0.1 degrees "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.25: Separation_of_two_lines_in_first_order_spectrum.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.25:: Page-3.46 (2009)\n",
+"clc; clear;\n",
+"lambda1 = 5500e-008;    // First wavelength, cm\n",
+"lambda2 = 3700e-008;    // Second wavelength, cm\n",
+"N = 15000;           // No. of lines per inch of grating, lines/inch\n",
+"a_plus_b = 2.54/N;         // Grating element, cm\n",
+"f = 120;        // Focal length of the lens, cm\n",
+"n = 1;      // Order of diffraction for principal maxima\n",
+"// As (a+b)*sin(theta_n) = n*lambda, solving for theta1 and theta2\n",
+"theta1 = asind(n*lambda1/a_plus_b);     // Direction of principal maxima with lambda1, degrees\n",
+"theta2 = asind(n*lambda2/a_plus_b);     // Direction of principal maxima with lambda2, degrees\n",
+"// As tand(theta) = x/f, solving for x1 - x2 = dx\n",
+"dx = f*(tand(theta1)-tand(theta2));     // Linear separation of two lines in first order spectrum, cm\n",
+"\n",
+"printf('\nThe linear separation of two lines in first order spectrum = %5.2f cm', dx);\n",
+"\n",
+"// Result \n",
+"// The linear separation of two lines in first order spectrum = 14.34 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.26: Difference_in_the_deviation_in_the_first_and_third_order_spectra.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.26:: Page-3.47 (2009)\n",
+"clc; clear;\n",
+"lambda = 5000e-008;    // Wavelength of light used, cm\n",
+"N = 5000;           // No. of lines per cm of grating, lines/cm\n",
+"a_plus_b = 1/N;         // Grating element, cm\n",
+"n = 1;      // Order of diffraction for first order spectra\n",
+"// As (a+b)*sin(theta_n) = n*lambda, solving for theta for first and third orders\n",
+"theta1 = asind(n*lambda/a_plus_b);     // Direction of principal maxima with lambda1, degrees\n",
+"n = 3;      // Order of diffraction for third order spectra\n",
+"theta3 = asind(n*lambda/a_plus_b);     // Direction of principal maxima with lambda2, degrees\n",
+"delta_theta = theta3 - theta1;  // Angular separation in the first and third order spectra, \n",
+"\n",
+"printf('\nThe difference in the deviation in the first and third order spectra = %4.1f degrees', delta_theta);\n",
+"\n",
+"// Result \n",
+"// The difference in the deviation in the first and third order spectra = 34.1 degrees "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.27: Order_of_diffraction_for_the_given_grating_element_and_wavelength_of_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.27:: Page-3.48 (2009)\n",
+"clc; clear;\n",
+"lambda = 6500e-008;    // Wavelength of light used, cm\n",
+"N = 10000;           // No. of lines per cm of grating, lines/cm\n",
+"a_plus_b = 1/N;         // Grating element, cm\n",
+"theta_n = 90;   // Direction for maximum possible orders, degrees\n",
+"// As (a+b)*sin(theta_n) = n*lambda, solving for theta for n\n",
+"n = a_plus_b*sind(theta_n)/lambda;  // Order of diffraction for \n",
+"\n",
+"printf('\nThe order of diffraction for the given grating element and wavelength of light = %d', n);\n",
+"\n",
+"// Result \n",
+"// The order of diffraction for the given grating element and wavelength of light = 1 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.28: Number_of_lines_ruled_on_the_grating_surface.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.28:: Page-3.48 (2009)\n",
+"clc; clear;\n",
+"lambda1 = 6500e-008;    // Wavelength of first line, cm\n",
+"lambda2 = 4500e-008;    // Wavelength of scecond line, cm\n",
+"theta1 = 18;        // Direction of lower order, degrees\n",
+"theta2 = 18;        // Direction of higher order, degrees\n",
+"// As (a+b)*sin(theta1) = n*lambda1 and (a+b)*sin(theta2) = (n+1)*lambda2, solving for n\n",
+"n = lambda2/(lambda1 - lambda2);    // Order of diffraction for first wavelength\n",
+"// As a_plus_b = n*lambda1/sind(theta1), solving for a_plus_b\n",
+"a_plus_b = ceil(n)*lambda1/sind(theta1);  // Grating element, cm\n",
+"N = 1/a_plus_b;     // No. of lines on the grating surface, lines/cm\n",
+"\n",
+"printf('\nThe number of lines ruled on the grating surface = %4d lines/cm', N);\n",
+"\n",
+"// Result \n",
+"// The number of lines ruled on the grating surface = 1584 lines/cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.29: Angles_at_which_first_and_second_order_maxima_are_observed.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.29:: Page-3.48 (2009)\n",
+"clc; clear;\n",
+"lambda = 6328e-008;    // Wavelength of He-Laser, cm\n",
+"a_plus_b = 1/6000;      // Grating element, cm\n",
+"n = 1;      // First order of diffraction for given wavelength\n",
+"// As (a+b)*sin(theta1) = n*lambda, solving for theta1\n",
+"theta1 = asind(n*lambda/a_plus_b);      // Angle at which first order maximum is observed, degrees\n",
+"n = 2;      // second order of diffraction for given wavelength\n",
+"theta2 = asind(n*lambda/a_plus_b);      // Angle at which second order maximum is observed, degrees\n",
+"\n",
+"printf('\nThe angle at which first order maximum is observed = %4.1f degrees', theta1);\n",
+"printf('\nThe angle at which second order maximum is observed = %4.1f degrees', theta2);\n",
+"\n",
+"// Result \n",
+"// The angle at which first order maximum is observed = 22.3 degrees\n",
+"// The angle at which second order maximum is observed = 49.4 degrees "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.2: Zone_plate_with_a_point_source_of_light_on_the_axis.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.2:: Page-3.9 (2009)\n",
+"clc; clear;\n",
+"v1 = 36;     // Position of the strongest image from the zone plate, cm\n",
+"v2 = 9;     // Position of the next image from the zone plate, cm\n",
+"lambda = 5890e-008;  // Wavelength of light used, cm\n",
+"r1 = 1;   // For simplicity assume radius of first ring of zone plate to be unity, cm\n",
+"n = 1;  // Order of zone plate\n",
+"// As 1/v1-1/u = n*lambda/r1^2 = 1/3*(1/v2-1/u), solving for u\n",
+"u = 2/(3/36-1/9);       // Distance of the zone plate from source, cm\n",
+"// As 1/v-1/u = n*lambda/r1^2, solving for r1\n",
+"r1 = sqrt(lambda/(1/v1-1/abs(u)));       // Radius of first zone, cm\n",
+"f1 = r1^2/(n*lambda);   // Principal focal length, cm\n",
+"\n",
+"printf('\nThe distance of the zone plate from source = %2d cm', u);\n",
+"printf('\nThe radius of first zone = %3.1e cm', r1);\n",
+"printf('\nThe principal focal length = %4.1f cm', f1);\n",
+"\n",
+"// Result \n",
+"// The distance of the zone plate from source = -72 cm\n",
+"// The radius of first zone = 6.5e-002 cm\n",
+"// The principal focal length = 72.0 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.30: Least_width_of_plane_transmission_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.30:: Page-3.49 (2009)\n",
+"clc; clear;\n",
+"lambda1 = 5890e-008;    // Wavelength of D1 line of Na, cm\n",
+"lambda2 = 5896e-008;    // Wavelength of D2 line of Na, cm\n",
+"d_lambda = lambda2-lambda1;      // Linear separation of two lines just seen as separate, cm\n",
+"P = 500;        // Number of lines per cm on grating, lines/cm\n",
+"n = 2;      // Order of diffraction\n",
+"// As resolving power of grating, lambda/d_lambda = n*N, solving for N\n",
+"N = lambda1/(d_lambda*n);    // No. of lines required per cm on grating, lines/cm\n",
+"w = N/P;        // Least width of grating, cm\n",
+"\n",
+"printf('\nThe least width of plane transmission grating = %5.3f cm', w);\n",
+"\n",
+"// Result \n",
+"// The least width of plane transmission grating = 0.982 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.31: Minimum_grating_width_required_to_resolve_two_wavelengths.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.31:: Page-3.49 (2009)\n",
+"clc; clear;\n",
+"theta1 = 18;        // Direction at which first spectral line appears, degrees\n",
+"theta2 = 18+5/(60*60);  // Direction at which second spectral line appears, degrees\n",
+"d_theta = (theta2-theta1)*%pi/180;       // Angular separation of two spectral lines, radians\n",
+"d_lambda = 50e-010;      // Linear separation of two spectral lines just seen as separate, cm\n",
+"DP = d_theta/d_lambda;      // Dispersive power of grating\n",
+"n = 1;      // Order of diffraction\n",
+"// As dispersive power of grating d_theta/d_lambda = DP = n/((a_plus_b)*cosd(theta1)), solving for a_plus_b\n",
+"a_plus_b = n/(DP*cosd(theta1));     // Grating element, cm\n",
+"// But a_plus_b*sind(theta1)=n*lambda1, solving for lambda1\n",
+"lambda1 = a_plus_b*sind(theta1)/n;      // Wavelength of first spectral line, cm\n",
+"lambda2 = lambda1+d_lambda/1e-002;             // Wavelength of second spectral line, cm\n",
+"// As resolving power of grating, lambda/d_lambda = n*N, solving for N\n",
+"N = lambda1/(d_lambda*n);    // No. of lines required per cm on grating\n",
+"w = N*a_plus_b;     // Minimum grating width required to resolve two wavelengths, cm\n",
+"\n",
+"printf('\nThe wavelength of first spectral line = %4.0f angstrom', lambda1/1e-008);\n",
+"printf('\nThe wavelength of second spectral line = %4.0f angstrom', lambda2/1e-008);\n",
+"printf('\nThe minimum grating width required to resolve two wavelengths = %3.1f cm', w);\n",
+"\n",
+"// Result \n",
+"// The wavelength of first spectral line = 6702 angstrom\n",
+"// The wavelength of second spectral line = 6752 angstrom\n",
+"// The minimum grating width required to resolve two wavelengths = 2.9 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.32: Angle_of_diffraction_for_maxima_in_first_order.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.32:: Page-3.50 (2009)\n",
+"clc; clear;\n",
+"// Function to convert theta into degree-minute\n",
+"function[degre, minute]=deg_2_degminsec(theta)\n",
+"    degre = floor(theta);\n",
+"    minute = (theta-floor(theta))*60;\n",
+"endfunction\n",
+"\n",
+"N = 15000;      // No. of lines on the grating per inch, lines/inch\n",
+"a_plus_b = 2.54/N;      // Grating element, cm\n",
+"lambda = 6000e-008;     // Wavelength of light used, cm\n",
+"n = 1;      // Order of diffraction spectra\n",
+"// But a_plus_b*sind(theta)=n*lambda, solving for theta\n",
+"theta = asind(n*lambda/a_plus_b);       // Direction in which first order spectra is seen, degrees\n",
+"[deg, mint] = deg_2_degminsec(theta);\n",
+"printf('\nThe angle of diffraction for maxima in first order = %2d degrees %2d min', deg, mint);\n",
+"\n",
+"// Result \n",
+"// The angle of diffraction for maxima in first order = 20 degrees 45 min "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.33: Wavelength_of_light_used_in_obtaining_second_order_diffraction_maximum.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.33:: Page-3.50 (2009)\n",
+"clc; clear;\n",
+"N = 12000;      // No. of lines on the grating per inch, lines/inch\n",
+"a_plus_b = 2.54/N;      // Grating element, cm\n",
+"n = 2;      // Order of diffraction spectra\n",
+"theta = 39; // Angle of diffraction for maxima in second order, degrees\n",
+"// But a_plus_b*sind(theta)=n*lambda, solving for lambda\n",
+"lambda = a_plus_b*sind(theta)/n;     // Wavelength of light used, cm\n",
+"\n",
+"printf('\nThe wavelength of light used in obtaining second order diffraction maximum = %4d angstrom', lambda/1e-008);\n",
+"\n",
+"// Result \n",
+"// The wavelength of light used in obtaining second order diffraction maximum = 6660 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.34: Number_of_visible_orders_using_diffraction_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.34:: Page-3.51 (2009)\n",
+"clc; clear;\n",
+"lambda = 5890e-008;     // Wavelength of light used, cm\n",
+"N = 6000;      // No. of lines on the grating per inch, lines/inch\n",
+"a_plus_b = 2.54/N;      // Grating element, cm\n",
+"theta_max = 90;     // Direction of maxima for maximum possible orders\n",
+"// But a_plus_b*sind(theta_max)=n*lambda, solving for n\n",
+"n = a_plus_b*sind(theta_max)/lambda;     // Number of visible orders\n",
+"\n",
+"printf('\nThe number of visible orders using diffraction grating = %d', n);\n",
+"\n",
+"// Result \n",
+"// The number of visible orders using diffraction grating = 7 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.35: Distance_between_two_wavelengths_seen_as_separate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.35:: Page-3.51 (2009)\n",
+"clc; clear;\n",
+"lambda = 5500e-008;     // Mean of two wavelengths, cm\n",
+"theta = 35;         // Angle of diffraction for maxima in second order\n",
+"d_theta = 0.15;     // Angular separation between two neighbouring wavelengths, radians\n",
+"d_lambda = lambda*cotd(theta)*d_theta;  // Distance between two wavelengths seen as separate, cm\n",
+"\n",
+"printf('\nThe distance between two wavelengths seen as separate = %d angstrom', d_lambda/1e-008);\n",
+"\n",
+"// Result \n",
+"// The distance between two wavelengths seen as separate = 1178 angstrom "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.36: Number_of_lines_per_cm_on_grating_surface.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.36:: Page-3.51 (2009)\n",
+"clc; clear;\n",
+"lambda1 = 5500e-008;     // First wavelength of light, cm\n",
+"lambda2 = 4500e-008;     // Second wavelength of light, cm\n",
+"theta = 45;     // Angle of diffraction for lower order, degrees\n",
+"n = lambda2/(lambda1-lambda2);  // Lower order of diffraction\n",
+"// But a_plus_b*sind(theta)=n*lambda, solving for a_plus_b\n",
+"a_plus_b = floor(n)*lambda1/sind(theta);       // Grating element, cm\n",
+"N = 1/a_plus_b;     // No. of lines per cm on grating surface, lines/cm\n",
+"\n",
+"printf('\nThe number of lines per cm on grating surface = %4d lines/cm', ceil(N));\n",
+"\n",
+"// Result \n",
+"// The number of lines per cm on grating surface = 3215 lines/cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.37: Total_number_of_lines_on_grating_surface.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.37:: Page-3.52 (2009)\n",
+"clc; clear;\n",
+"lambda = 6500e-008;     // Wavelength of light used, cm\n",
+"theta = 19.5;   // Angle of diffraction for maxima in first order, degrees\n",
+"l = 3.5;    // Length of the grating, cm\n",
+"n = 1;      // Order of diffraction\n",
+"// But a_plus_b*sind(theta)=n*lambda, solving for a_plus_b\n",
+"a_plus_b = n*lambda/sind(theta);       // Grating element, cm\n",
+"N = 1/a_plus_b;     // No. of lines per cm on grating surface, lines/cm\n",
+"N_total = l*N;      // Total number of lines on grating surface\n",
+"\n",
+"printf('\nThe total number of lines on grating surface = %5d', N_total);\n",
+"\n",
+"// Result \n",
+"// The total number of lines on grating surface = 17974 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.38: Angular_separation_between_the_sodium_D1_and_D2_lines.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.38:: Page-3.52 (2009)\n",
+"clc;clear;\n",
+"function [mint, secnd]=degmin(theta)\n",
+"    mint = (theta-floor(theta))*60;\n",
+"    secnd = (mint-floor(mint))*60\n",
+"endfunction\n",
+"lambda_D1 = 5890e-008;  // Wavelength of sodium D1 line, cm\n",
+"lambda_D2 = 5896e-008;  // Wavelength of sodium D2 line, cm\n",
+"n = 2;  // Order of diffraction\n",
+"N = 6500;   // Number of lines per cm on grating, lines/cm\n",
+"a_plus_b = 1/6500;  // Grating element, cm\n",
+"// As a_plus_b*sin(theta1)=n*lambda1, solving for theta1\n",
+"theta1 = asind(n*lambda_D1/a_plus_b);\n",
+"// As a_plus_b*sin(theta2)=n*lambda2, solving for theta1\n",
+"theta2 = asind(n*lambda_D2/a_plus_b);\n",
+"d_theta = theta2-theta1;    // Angular separation between the sodium D1 and D2 lines, degrees\n",
+"[mint, secnd] = degmin(d_theta);  // Call deg_2_degmin function\n",
+"printf('\nThe angular separation between the sodium D1 and D2 lines = %d minutes %d seconds', mint, secnd);\n",
+"// Result\n",
+"// The angular separation between the sodium D1 and D2 lines = 4 minutes 10 seconds \n",
+"// Since theta1 and theta2 are rounded off in the textbook, therefore the answer is mismatching."
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.39: Minimum_number_of_lines_in_a_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.39:: Page-3.55 (2009)\n",
+"clc;clear;\n",
+"lambda1 = 5890e-008;  // Wavelength of sodium D1 line, cm\n",
+"lambda2 = 5896e-008;  // Wavelength of sodium D2 line, cm\n",
+"d_lambda = lambda2-lambda1; // Difference in the wavelength of two lines, cm\n",
+"n = 2;  // Order of diffraction\n",
+"// As lambda/d_lambda = n*N, solving for N\n",
+"N = lambda1/(d_lambda*n);  // Minimum number of lines in a grating\n",
+"printf('\nThe minimum number of lines in a grating = %3d lines', N);\n",
+"// Result\n",
+"// The minimum number of lines in a grating = 490 lines "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.3: Position_of_the_first_image_in_a_zone_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.3:: Page-3.10 (2009)\n",
+"clc; clear;\n",
+"lambda = 5500e-010;  // Wavelength of light used, cm\n",
+"u = -4;     // Distance of the zone plate from source, cm\n",
+"D = 3.7e-003;   // Diameter of central zone of zone plate, cm\n",
+"r = D/2;    // Radius of central zone of zone plate, cm\n",
+"n = 1;  // Order of zone plate\n",
+"f1 = r^2/(n*lambda);        // Principal focal length, cm\n",
+"v1 = 36;     // Position of the strongest image from the zone plate, cm\n",
+"v2 = 9;     // Position of the next image from the zone plate, cm\n",
+"// As 1/v - 1/u = 1/f, solving for v\n",
+"v = 1/(1/f1+1/u);        // Position of the first image in a zone plate, cm\n",
+"\n",
+"printf('\nThe position of the first image in a zone plate = %2d cm', floor(v));\n",
+"\n",
+"// Result \n",
+"// The position of the first image in a zone plate = -12 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.40: Linear_separation_of_two_points_on_the_moon.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.40:: Page-3.56 (2009)\n",
+"clc;clear;\n",
+"lambda = 5500e-008;  // Wavelength of most sensitive color to an eye, cm\n",
+"a = 400;    // Aperture of the telescope, cm\n",
+"D = 3.8e+010;   // Distance of the moon from the earth, cm\n",
+"d_theta = 1.22*lambda/a;    // Limit of resolution of telescope, radians\n",
+"// As d_theta = x/D, solving for x\n",
+"x = d_theta*D;  // Linear separation of two points on the moon, cm\n",
+"printf('\nThe linear separation of two points on the moon = %5.2f m', x/1e+002);\n",
+"// Result\n",
+"// The linear separation of two points on the moon = 63.74 m "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.41: Minimum_required_number_of_lines_on_the_plane_transmission_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.41:: Page-3.56 (2009)\n",
+"clc;clear;\n",
+"lambda1 = 5890e-008;  // Wavelength of sodium D1 line, cm\n",
+"lambda2 = 5896e-008;  // Wavelength of sodium D2 line, cm\n",
+"d_lambda = lambda2-lambda1; // Wavelength difference, cm\n",
+"n = 2;      // Order of diffraction\n",
+"// As lambda/d_lambda = n*N, solving for N\n",
+"N = 1/n*(lambda1+lambda2)/(2*d_lambda);    // Minimum required number of lines on the plane transmission grating\n",
+"printf('\nThe minimum required number of lines on the plane transmission grating = %3d', N);\n",
+"// Result\n",
+"// The minimum required number of lines on the plane transmission grating = 491  "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.42: EX3_42.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.42:: Page-3.57 (2009)\n",
+"clc;clear;\n",
+"lambda1 = 5890e-008;  // Wavelength of sodium D1 line, cm\n",
+"lambda2 = 5896e-008;  // Wavelength of sodium D2 line, cm\n",
+"d_lambda = lambda2-lambda1; // Wavelength difference, cm\n",
+"w = 2.5;    // Width of the grating, cm\n",
+"n = 2;      // Order of diffraction\n",
+"// As lambda/d_lambda = n*N, solving for N\n",
+"N = 1/n*(lambda1+lambda2)/(2*d_lambda);    // Minimum required number of lines on the plane transmission grating\n",
+"printf('\nThe number of lines on the plane transmission grating to just resolve the sodium lines = %3d', N/w);\n",
+"// Result\n",
+"// The number of lines on the plane transmission grating to just resolve the sodium lines = 196 "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.43: Minimum_width_of_the_grating_to_resolve_the_sodium_lines_in_third_order.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.43:: Page-3.57 (2009)\n",
+"clc;clear;\n",
+"lambda1 = 5890e-008;  // Wavelength of sodium D1 line, cm\n",
+"lambda2 = 5896e-008;  // Wavelength of sodium D2 line, cm\n",
+"d_lambda = lambda2-lambda1; // Wavelength difference, cm\n",
+"n = 3;      // Order of diffraction\n",
+"P = 2500;   // Number of lines per unit length of grating\n",
+"// As lambda/d_lambda = n*N, solving for N\n",
+"N = 1/n*(lambda1+lambda2)/(2*d_lambda);    // Total lines on the grating \n",
+"w = N/P;    // Minimum width of the grating, cm\n",
+"printf('\nThe minimum width of the grating to resolve the sodium lines in third order = %5.3f cm', w);\n",
+"// Result\n",
+"// The minimum width of the grating to resolve the sodium lines in third order = 0.131 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.44: Dispersive_power_and_diffraction_angle_for_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.44:: Page-3.57 (2009)\n",
+"clc;clear;\n",
+"w = 2;      // Width of the grating, cm\n",
+"P = 4500;   // Total number of lines on the grating\n",
+"a_plus_b = w/P; // Grating element, cm\n",
+"lambda1 = 5890e-008;  // Wavelength of sodium D1 line, cm\n",
+"lambda2 = 5896e-008;  // Wavelength of sodium D2 line, cm\n",
+"lambda = (lambda1+lambda2)/2;  // Mean wavelength of light used, cm\n",
+"d_lambda=lambda2-lambda1;   // Difference in wavelengths of D-lines of sodium, cm\n",
+"n = 2;  // Order of diffraction\n",
+"// As a_plus_b*sind(theta)=n*lambda, solving for theta\n",
+"theta = asind(n*lambda/a_plus_b);   // Angle of diffraction, degrees\n",
+"DP = n/(a_plus_b*cosd(theta));      // Dispersive power of grating\n",
+"d_theta = DP*d_lambda*180/%pi;  // Angular separation between D-lines, degrees\n",
+"RP = lambda/d_lambda;   // Required resolving power of grating for sodium lines\n",
+"N = 2.54/a_plus_b;  // No. of lines per cm on grating, lines/cm\n",
+"RP_cal = n*N;       // Calculated resolving power of grating  \n",
+"printf('\nThe angle of diffraction for maxima in second order = %6.4f degrees', d_theta);\n",
+"printf('\nAs %5.3e > %3d, D-lines can be resolved.', RP_cal, RP);\n",
+"// Result\n",
+"// The angle of diffraction for maxima in second order = 0.0160 degrees\n",
+"// As 1.143e+04 > 982, D-lines can be resolved. "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.45: Distance_between_centres_of_images_of_the_two_stars.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.45:: Page-3.58 (2009)\n",
+"clc;clear;\n",
+"lambda = 5500e-010;  // Wavelength of light used, m\n",
+"a = 0.01;   // Diameter of objective of telescope, m\n",
+"f = 3.0;    // Focal length of tlescope objective, m \n",
+"// For telescope, the limit of resolution, \n",
+"// theta = x/f = 1.22*lambda/a, solving for x\n",
+"x = 1.22*lambda/a*f;    // Distance between centres of imgaes of the two stars\n",
+"printf('\nThe distance between centres of imgaes of the two stars = %4.2e m', x);\n",
+"// Result\n",
+"// The distance between centres of imgaes of the two stars = 2.01e-04 m "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.46: Aperture_of_the_objective_of_the_microscope.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code EX3.46:: Page-3.59 (2009)\n",
+"clc;clear;\n",
+"lambda = 5461e-008;  // Wavelength of light used, cm\n",
+"d = 4e-005;     // Separation distance between two self-luminous objects, cm\n",
+"NA = 1.22*lambda/(2*d);     // Numerical aperture of microscope, cm\n",
+"printf('\nThe numerical aperture of the objective of the microscopes = %6.4f cm', NA);\n",
+"// Result\n",
+"// The numerical aperture of the objective of the microscopes = 0.8328 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.4: Principal_focal_length_of_zone_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.4:: Page-3.11 (2009)\n",
+"clc; clear;\n",
+"lambda = 1;     // For simplicity assume wavelength of light used to be unity, unit\n",
+"R = 150;        // Radius of curvature of the curved surface, cm\n",
+"r1 = sqrt(lambda*R);    // For Newton's ring, cm\n",
+"f1 = r1^2/lambda;       // Principal focal length of zone plate, cm\n",
+"\n",
+"printf('\nThe principal focal length of zone plate = %3d cm', f1);\n",
+"\n",
+"// Result \n",
+"// The principal focal length of zone plate = 150 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.5: Half_angular_width_at_central_maximum_in_Fraunhoffer_diffraction.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.5:: Page-3.22 (2009)\n",
+"clc; clear;\n",
+"lambda = 5000e-008;     // Wavelength of light used, cm\n",
+"a = 15e-005;    // Width of the slit, cm\n",
+"n = 1;      // Order of diffraction\n",
+"// For a single slit Fraunhofer diffraction, a*sin(theta) = n*lambda, solving for theta\n",
+"theta = asin(n*lambda/a);  // Half angular width at central maximum in Fraunhoffer diffraction, radian\n",
+"\n",
+"printf('\nThe half angular width at central maximum in Fraunhoffer diffraction = %5.3f rad', theta);\n",
+"\n",
+"// Result \n",
+"// The half angular width at central maximum in Fraunhoffer diffraction= 0.340 rad "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.6: Width_of_the_slit.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.6:: Page-3.23 (2009)\n",
+"clc; clear;\n",
+"lambda = 5000e-010;     // Wavelength of light used, cm\n",
+"n = 1;      // Order of diffraction\n",
+"x = 5e-003;     // Position of first minima on either sides of central maximum, m\n",
+"D = 2.5;    // Distance of screen from the narrow slir, m\n",
+"sin_theta = x/sqrt(x^2+D^2);    // Sine of angle theta, rad\n",
+"// For a single slit Fraunhofer diffraction, a*sin(theta) = n*lambda, solving for a\n",
+"a = n*lambda/sin_theta;     // Width of the slit, m\n",
+"\n",
+"printf('\nThe Width of the slit = %3.1e m', a);\n",
+"\n",
+"// Result \n",
+"// The Width of the slit = 2.5e-004 m "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7: Angular_width_of_central_maximum.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.7:: Page-3.23 (2009)\n",
+"clc; clear;\n",
+"lambda = 6000e-010;     // Wavelength of light used, m\n",
+"a = 15e-007;    // Width of the slit, m\n",
+"// For a single slit Fraunhofer diffraction, a*sind(theta) = n*lambda, solving for theta\n",
+"theta = asind(lambda/a); // Half angular width of central maximum, degrees\n",
+"\n",
+"printf('\nThe angular width of central maximum = %2d degrees', 2*ceil(theta));\n",
+"\n",
+"// Result \n",
+"// The angular width of central maximum = 48 degrees "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.8: Distance_between_first_minima_and_the_next_minima_from_the_axis.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.8:: Page-3.23 (2009)\n",
+"clc; clear;\n",
+"lambda = 5000e-010;     // Wavelength of light used, m\n",
+"a = 0.7e-002;    // Width of the slit, m\n",
+"f = 0.5;        // Focal length of the lens, m\n",
+"n = 1;      // Order of diffraction\n",
+"// For minima, a*sind(theta_n) = n*lambda\n",
+"// Also theta_n = n*lambda/a = x1/f, solving for x1\n",
+"x1 = f*n*lambda/a;        // Position of first minima, cm\n",
+"// For secondary maxima, a*sind(theta_n) = (2*n+1)*lambda/2\n",
+"// Also theta_n = 3*lambda/(2*a) = x2/f, solving for x2\n",
+"n = 1;      // Order of diffraction for first secondary minima\n",
+"x2 = 3*f*lambda/(2*a);      // Position of first secondary maxima, cm\n",
+"\n",
+"printf('\nThe distance between first minima and the next minima from the axis = %4.2e cm', x2-x1);\n",
+"\n",
+"// Result \n",
+"// The distance between first minima and the next minima from the axis = 1.79e-005 cm "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.9: Width_of_central_maxima_in_diffraction_pattern.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Scilab Code Ex3.9:: Page-3.24 (2009)\n",
+"clc; clear;\n",
+"lambda = 6600e-008;     // Wavelength of light used, cm\n",
+"a = 0.018;    // Width of the slit, cm\n",
+"f = 200;        // Focal length of the lens, cm\n",
+"n = 1;      // Order for first order diffraction\n",
+"// As a*sin(theta) = n*lambda, a*theta = n*lambda\n",
+"// As theta = lambda/a and theta = x/f, solving for x\n",
+"x = lambda*f/a;     // Half angular width at central maximum, cm\n",
+"\n",
+"printf('\nThe width of central maximum = %3.1f cm', 2*x);\n",
+"\n",
+"// Result \n",
+"// The width of central maximum = 1.5 cm "
+   ]
+   }
+],
+"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
+}