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diff --git a/Engineering_Physics_by_U_Mukherji/1-Crystallography_And_Crystal_Imperfection.ipynb b/Engineering_Physics_by_U_Mukherji/1-Crystallography_And_Crystal_Imperfection.ipynb
new file mode 100644
index 0000000..d675309
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/1-Crystallography_And_Crystal_Imperfection.ipynb
@@ -0,0 +1,127 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 1: Crystallography And Crystal Imperfection"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.1: density_of_metal.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter-1,Example1_1,pg 40\n",
+"\n",
+"n=4\n",
+"\n",
+"M=65.34\n",
+"\n",
+"N=6.023*10^23\n",
+"\n",
+"d111=2.08*10^-8//interplannar spacing\n",
+"\n",
+"a=d111*sqrt((1^2)+(1^2)+(1^2))\n",
+"\n",
+"D=(n*M)/(N*(a^3))\n",
+"\n",
+"printf('density of Cu-metal\n')\n",
+"\n",
+"printf('D=%.2f g/cc',D)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.2: find_intercepts_along_crystal_axis.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter-1,Example1_2,pg 40\n",
+"\n",
+"//miller plane 231\n",
+"\n",
+"a=1.2*10^-10\n",
+"\n",
+"b=1.8*10^-10\n",
+"\n",
+"c=2*10^-10//primitives of crystal\n",
+"\n",
+"//intercepts of ABC plane\n",
+"\n",
+"a1=a/2\n",
+"\n",
+"b1=b/3\n",
+"\n",
+"c1=c/1\n",
+"\n",
+"//intercept of ABC plane along X-axis =0.6*10^-10\n",
+"\n",
+"//ABC is not the reqd. plane\n",
+"\n",
+"//intercept of DEF plane parallel to ABC\n",
+"\n",
+"a2=a\n",
+"\n",
+"b2=(2*b)/3\n",
+"\n",
+"c2=2*c\n",
+"\n",
+"//miller indices for DEF\n",
+"\n",
+"//1:(3/2):(1/2)\n",
+"\n",
+"printf('intercept of DEF plane\n')\n",
+"\n",
+"printf('along x-axis=%.11f\n',a2)\n",
+"\n",
+"printf('along y-axis=%.11f\n',b2)\n",
+"\n",
+"printf('\nalong z-axis=%.11f',c2)\n",
+"\n",
+"printf('\nDEF is the reqd. plane')"
+   ]
+   }
+],
+"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_U_Mukherji/10-Motion_Of_Charged_Particle_In_Electric_And_Magnetic_Field.ipynb b/Engineering_Physics_by_U_Mukherji/10-Motion_Of_Charged_Particle_In_Electric_And_Magnetic_Field.ipynb
new file mode 100644
index 0000000..83db68c
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/10-Motion_Of_Charged_Particle_In_Electric_And_Magnetic_Field.ipynb
@@ -0,0 +1,608 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 10: Motion Of Charged Particle In Electric And Magnetic Field"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.10: charge_on_drop.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_10,pg 275\n",
+"\n",
+"//F=mg=qE\n",
+"\n",
+"E=250\n",
+"\n",
+"R=10^-8\n",
+"\n",
+"rho=10^3//density\n",
+"\n",
+"m=(4/3)*%pi*(R^3)*rho//m=volume*density\n",
+"\n",
+"W=m*9.8//weight of drop(mg)\n",
+"\n",
+"q=W/E\n",
+"\n",
+"printf('charge on water drop\n')\n",
+"\n",
+"disp(q)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.11: bainbridge_mass_spectograph.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_11,pg 275\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"v=5*10^5\n",
+"\n",
+"B=0.3\n",
+"\n",
+"N=6.025*10^26\n",
+"\n",
+"M72=72/N\n",
+"\n",
+"R72=(M72*v)/(B*e)\n",
+"\n",
+"M74=74\n",
+"\n",
+"R74=(R72/72)*M74\n",
+"\n",
+"S=2*(R74-R72)//linear separation of two line\n",
+"\n",
+"printf('linear separation of two line\n')\n",
+"\n",
+"printf('S=%.2f m',S)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.12: calculate_flux_density.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_12,pg 276\n",
+"\n",
+"l=5*10^-2\n",
+"\n",
+"d=0.3//distance of screen from end of mag. field\n",
+"\n",
+"D=d+(l/2)\n",
+"\n",
+"y=0.01\n",
+"\n",
+"m=9.1*10^-31\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"Va=1000\n",
+"\n",
+"B=(y/(D*l))*sqrt((2*m*Va)/e)\n",
+"\n",
+"printf('flux density\n')\n",
+"\n",
+"printf('B=%.8f Wb/m2',B)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.13: electron_in_transverse_electric_field.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_13,pg 276\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"Va=150\n",
+"\n",
+"m=9.1*10^-31\n",
+"\n",
+"vx=sqrt((2*e*Va)/m)\n",
+"\n",
+"V=20\n",
+"\n",
+"d=10^-2\n",
+"\n",
+"ay=(e/m)*(V/d)\n",
+"\n",
+"l=10*10^-2\n",
+"\n",
+"vy=ay*(l/vx)\n",
+"\n",
+"theta=atan(vy/vx)\n",
+"\n",
+"theta=theta*(180/%pi)//converting into degree\n",
+"\n",
+"theta=theta*(%pi/180)//converting into radian\n",
+"\n",
+"Y=D*tan(theta)\n",
+"\n",
+"S=(Y/V)\n",
+"\n",
+"printf('velocity of electron reaching field vx=%.2f m/sec\n',vx)\n",
+"\n",
+"printf('\nacceleration due to electric field ay=%.2f m/sec2\n',ay)\n",
+"\n",
+"printf('\nfinal velocity attained by deflecting field vy=%.2f m/sec\n',vy)\n",
+"\n",
+"printf('\nangle of deflection theta=%.2f deg.\n',theta)\n",
+"\n",
+"printf('\ndeflection on screen Y=%.2f m\n',Y)\n",
+"\n",
+"printf('\ndeflection senstivity S=%.2f m/volt\n',S)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.1: find_KE_of_particle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_1,pg 270\n",
+"\n",
+"L=1.33*10^-22\n",
+"\n",
+"B=0.025\n",
+"\n",
+"m=6.68*10^-27\n",
+"\n",
+"q=3.2*10^-19\n",
+"\n",
+"w=(B*q)/m\n",
+"\n",
+"E=0.5*L*w//E=0.5I(w^2),Iw=L\n",
+"\n",
+"E=E/(1.6*10^-19)//converting into ev\n",
+"\n",
+"printf('KE of particle\n')\n",
+"\n",
+"printf('E=%.2f ev',E)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.2: frequency_of_oscillation_and_maximum_energy_of_particle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_2,pg 271\n",
+"\n",
+"R=0.35\n",
+"\n",
+"n=1.38*10^7\n",
+"\n",
+"m=1.67*10^-27\n",
+"\n",
+"q=1.6*10^-19\n",
+"\n",
+"B=(2*%pi*n*m)/q\n",
+"\n",
+"E=((B^2)*(q^2)*(R^2))/(2*m)\n",
+"\n",
+"E=E/q\n",
+"\n",
+"printf('magnetic field induction\n')\n",
+"\n",
+"printf('B=%.2f wb/m2',B)\n",
+"\n",
+"printf('\nmaximum energy of proton\n')\n",
+"\n",
+"printf('E=%.2f ev',E)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.3: radius_of_electron_trajectory_and_angular_momentum.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_3,pg 271\n",
+"\n",
+"m=9.1*10^-31\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"//due to potential difference V, electron is accelerated\n",
+"\n",
+"//eV=0.5*m*(v^2)\n",
+"\n",
+"//due to transverse magnetic field B electron moves in circular path of radius R\n",
+"\n",
+"//(m*(v^2))/R=BeV\n",
+"\n",
+"B=1.19*10^-3\n",
+"\n",
+"V=1000\n",
+"\n",
+"v=sqrt((2*e*V)/m)\n",
+"\n",
+"R=(m*v)/(B*e)\n",
+"\n",
+"L=m*v*R\n",
+"\n",
+"printf('radius of electron trajectory\n')\n",
+"\n",
+"printf('R=%.2f m',R)\n",
+"\n",
+"printf('\nangular momentum of electron\n')\n",
+"\n",
+"disp(L)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.4: vertical_displacement_and_magnetic_field_of_electron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_4,pg 272\n",
+"\n",
+"vx=1.7*10^7\n",
+"\n",
+"Ey=3.4*10^4\n",
+"\n",
+"x=3*10^-2\n",
+"\n",
+"t=x/vx\n",
+"\n",
+"//y=0.5*ay*(t^2)\n",
+"\n",
+"ay=(e*Ey)/m\n",
+"\n",
+"y=0.5*ay*(t^2)\n",
+"\n",
+"Bz=Ey/vx\n",
+"\n",
+"printf('verical displacement of electron \n')\n",
+"\n",
+"printf('y=%.2f m',y)\n",
+"\n",
+"printf('\nmagnitude of magnetic field\n')\n",
+"\n",
+"printf('B=%.4f wb/m2',B)\n",
+"\n",
+"printf('\ndirection of field is upward as Ey is downward')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.5: resonance_frequency_and_maximum_energy_of_proton.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_5,pg 272\n",
+"\n",
+"m=1.67*10^-27\n",
+"\n",
+"q=1.6*10^-19\n",
+"\n",
+"B=0.5\n",
+"\n",
+"n=((B*q)/(2*%pi*m))\n",
+"\n",
+"R=1\n",
+"\n",
+"E=((B^2)*(q^2)*(R^2))/(2*m)\n",
+"\n",
+"E=E/(1.6*10^-19)\n",
+"\n",
+"printf('frequency of oscillation voltage\n')\n",
+"\n",
+"printf('n=%.2f Hz',n)\n",
+"\n",
+"printf('\nmaximum energy of proton\n')\n",
+"\n",
+"printf('E=%.2f ev',E)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.6: calculate_force_periodic_time_and_resonance_frequency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_6,pg 273\n",
+"\n",
+"q=3.2*10^-19\n",
+"\n",
+"m=6.68*10^-27\n",
+"\n",
+"B=1.5\n",
+"\n",
+"v=7.263*10^6\n",
+"\n",
+"F=B*q*v\n",
+"\n",
+"printf('force on particle\n')\n",
+"\n",
+"disp(F)\n",
+"\n",
+"T=(2*%pi*m)/(B*q)\n",
+"\n",
+"n=1/T\n",
+"\n",
+"printf('\nperiodic time\n')\n",
+"\n",
+"disp(T)\n",
+"\n",
+"printf('\nresonance frequency\n')\n",
+"\n",
+"printf('n=%.2f Hz',n)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.7: calculate_flux_density_and_radius_of_cyclotron_for_proton_and_alpha_particle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_7,pg 273\n",
+"\n",
+"n=1.2*10^7\n",
+"\n",
+"mp=1.67*10^-27\n",
+"\n",
+"qp=1.6*10^-19\n",
+"\n",
+"Bp=(2*%pi*mp*n)/qp\n",
+"\n",
+"R=0.5\n",
+"\n",
+"Ep=((Bp^2)*(qp^2)*(R^2))/(2*mp)\n",
+"\n",
+"Ep=Ep/qp\n",
+"\n",
+"malp=6.68*10^-27\n",
+"\n",
+"qalp=2*1.6*10^-19\n",
+"\n",
+"Balp=(2*%pi*malp*n)/qalp\n",
+"\n",
+"Ealp=((Balp^2)*(qalp^2)*(R^2))/(2*malp)\n",
+"\n",
+"Ealp=Ealp/qp\n",
+"\n",
+"printf('flux density for proton\n')\n",
+"\n",
+"printf('Bp=%.2f Wb/m2',Bp)\n",
+"\n",
+"printf('\nflux density for alpha particle\n')\n",
+"\n",
+"printf('Balp=%.2f Wb/m2',Balp)\n",
+"\n",
+"printf('\nenergy of proton\n')\n",
+"\n",
+"printf('Ep=%.2f ev',Ep)\n",
+"\n",
+"printf('\nenergy of alpha particle\n') \n",
+"\n",
+"printf('Ealp=%.2f ev',Ealp)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.8: linear_separation_of_electron_beam.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_8,pg 274\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"me=9.1*10^-31//mass of electron\n",
+"\n",
+"q=3.2*10^-19\n",
+"\n",
+"malp=6.68*10^-27//mass of alpha particle\n",
+"\n",
+"B=0.05\n",
+"\n",
+"V=20*10^3\n",
+"\n",
+"//v=sqrt((2*q*V)/m)\n",
+"\n",
+"//R=(1/B)*sqrt((2*m*V)/q)\n",
+"\n",
+"Re=(1/B)*sqrt((2*me*V)/e)\n",
+"\n",
+"Ralp=(1/B)*sqrt((2*malp*V)/q)\n",
+"\n",
+"S=2*Ralp-2*Re//linear separation between two particles on common boundary wall\n",
+"\n",
+"printf('linear separation between two particles on common boundary wall\n')\n",
+"\n",
+"printf('S=%.2f m',S)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.9: find_potential_difference.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter10,Example10_9,pg 274\n",
+"\n",
+"V1=200\n",
+"\n",
+"//electrostatic focusing condition\n",
+"\n",
+"//(sini/sinr)=(v2/v1)=sqrt(V2/V1)\n",
+"\n",
+"//0.5mv2=eV\n",
+"\n",
+"i=60*(%pi/180)//converting into radian\n",
+"\n",
+"r=45*(%pi/180)//converting into radian\n",
+"\n",
+"V2=200*((sin(i)/sin(r))^2)\n",
+"\n",
+"pd=V2-V1//potential difference\n",
+"\n",
+"printf('potential difference between two region\n')\n",
+"\n",
+"printf('\npd=%.2f Volts',pd)"
+   ]
+   }
+],
+"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_U_Mukherji/11-Quantum_Physics_And_Schrodinger_Wave_Equation.ipynb b/Engineering_Physics_by_U_Mukherji/11-Quantum_Physics_And_Schrodinger_Wave_Equation.ipynb
new file mode 100644
index 0000000..1293be7
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/11-Quantum_Physics_And_Schrodinger_Wave_Equation.ipynb
@@ -0,0 +1,379 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 11: Quantum Physics And Schrodinger Wave Equation"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.1: uncertainity_in_velocity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter11,Example11_1,pg 298\n",
+"\n",
+"me=9.1*10^-31//masss of electron\n",
+"\n",
+"h=6.62*10^-34//planck's const.\n",
+"\n",
+"delx=10^-8//uncertainity in position\n",
+"\n",
+"delp=(h/(2*%pi*delx))//uncertainity principle\n",
+"\n",
+"delv=(delp/me)//uncertainity in velocity\n",
+"\n",
+"printf('uncertainity in velocity\n')\n",
+"\n",
+"printf('delv=%.2f m/sec',delv)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.2: find_KE_and_velocity_of_proton.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter11,Example11_2,pg 298\n",
+"\n",
+"lam=0.2865*10^-10//wavelength\n",
+"\n",
+"mp=1.67*10^-27//mass of proton\n",
+"\n",
+"h=6.625*10^-34\n",
+"\n",
+"v=(h/(mp*lam))//debroglie's equation\n",
+"\n",
+"KE=0.5*mp*(v^2)//kinetic energy of proton(J)\n",
+"\n",
+"KE=KE/(1.6*10^-19)//converting into ev\n",
+"\n",
+"printf('kinetic energy of proton\n')\n",
+"\n",
+"printf('KE=%.2f ev',KE)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.3: momentum_and_energy_of_electron_and_photon.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter11,Example11_3,pg 299\n",
+"\n",
+"KEnu=0.025*1.6*10^-19//kinetic energy of neutron\n",
+"\n",
+"mn=1.676*10^-27//mass of neutron\n",
+"\n",
+"v=sqrt((2*KEnu)/mn)\n",
+"\n",
+"h=6.626*10^-34\n",
+"\n",
+"lamn=h/(mn*v)//debroglie wavelength of neutron \n",
+"\n",
+"printf('wavelength of beam of neutron\n')\n",
+"\n",
+"printf('lamn=%.12f m',lamn)\n",
+"\n",
+"p=(h/lamn)\n",
+"\n",
+"printf('\nmomentum of electron and photon\n')\n",
+"\n",
+"printf('p=%.26f kgm/sec',p)\n",
+"\n",
+"me=9.1*10^-31//mass of electron\n",
+"\n",
+"ve=(p/me)//velocity of electron\n",
+"\n",
+"Ee=0.5*p*ve//energy of electron\n",
+"\n",
+"Ee=Ee/(1.6*10^-19)//convering into ev\n",
+"\n",
+"printf('\nenergy of electron\n')\n",
+"\n",
+"printf('Ee=%.2f ev',Ee)\n",
+"\n",
+"Ep=(h*3*10^8)/lamn//energy of photon\n",
+"\n",
+"Ep=Ep/(1.6*10^-19)\n",
+"\n",
+"printf('\nenergy of photon\n')\n",
+"\n",
+"printf('Ep=%.2f ev',Ep)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.4: find_mass_of_particle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter11,Example11_4,pg 300\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"V=200\n",
+"\n",
+"lam=0.0202*10^-10//debroglie wavelength\n",
+"\n",
+"h=6.625*10^-34\n",
+"\n",
+"//eV=0.5*m*(v^2)\n",
+"\n",
+"//mv=sqrt(2*m*eV)\n",
+"\n",
+"m=((h^2)/(2*(lam^2)*e*V))//mass of particle\n",
+"\n",
+"printf('mass of particle\n')\n",
+"\n",
+"disp(m)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.5: calculate_debroglie_wavelength_of_neutron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter11,Example11_5,pg 300\n",
+"\n",
+"mn=1.676*10^-27//mass of neutron\n",
+"\n",
+"h=6.625*10^-34\n",
+"\n",
+"En=1.6*10^-19//energy of neutron\n",
+"\n",
+"v=sqrt((2*En)/mn)\n",
+"\n",
+"lam=(h/(mn*v))//de-broglie wavelength\n",
+"\n",
+"printf('de-broglie wavelength\n')\n",
+"\n",
+"disp(lam)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.6: existence_of_electron_within_nucleus.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter11,Example11_6,pg 300\n",
+"\n",
+"//acc. to uncertainity principle\n",
+"\n",
+"//delx*delp >= (h/2*%pi)\n",
+"\n",
+"rad=10^-14\n",
+"\n",
+"delx=2*rad\n",
+"\n",
+"h=6.625*10^-34\n",
+"\n",
+"delp=(h/(2*%pi*delx))\n",
+"\n",
+"//from einstein's relavistic relation\n",
+"\n",
+"//E=mc2=KE+rest mass energy=0.5mv2+moc2\n",
+"\n",
+"//when velocity of particle is very high\n",
+"\n",
+"//m=(mo/sqrt(1-((v/c)^2)))\n",
+"\n",
+"//m-mass of particle with velocity v\n",
+"\n",
+"//mo-rest mass of particle\n",
+"\n",
+"//c-velocity of particle\n",
+"\n",
+"p=delp//assume\n",
+"\n",
+"c=3*10^8\n",
+"\n",
+"mo=9.1*10^-31\n",
+"\n",
+"E=sqrt(((p*c)^2)+((mo*(c^2))^2))\n",
+"\n",
+"E=E/(1.6*10^-19)\n",
+"\n",
+"printf('E=%.2f ev',E)\n",
+"\n",
+"printf('\nthis value is much higher than experimentally obtained values of energy of electron\n')\n",
+"\n",
+"printf('of a radioactive nuclei i.e 4 Mev this proves that electron cannot reside within nucleus')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.7: calculate_debroglie_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter11,Example11_7,pg 302\n",
+"\n",
+"m1=60*10^-9\n",
+"\n",
+"v1=80\n",
+"\n",
+"p1=m1*v1\n",
+"\n",
+"h=6.625*10^-34\n",
+"\n",
+"lam1=h/p1//de-broglie wavelength case-1\n",
+"\n",
+"m2=8*10^-27\n",
+"\n",
+"v2=1.3\n",
+"\n",
+"p2=m2*v2\n",
+"\n",
+"lam2=h/p2//de-broglie wavelength case-2\n",
+"\n",
+"printf('de-broglie wavelength for case-1\n')\n",
+"\n",
+"disp(lam1)\n",
+"\n",
+"printf('\nde-broglie wavelength for case-2\n')\n",
+"\n",
+"disp(lam2)\n",
+"\n",
+"printf('\nfrom case-1 it is clear that for normal particles de-broglie wavelength is not visible it is very small')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.8: calculate_KE_of_electro.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter11,Example11_8,pg 302\n",
+"\n",
+"h=6.634*10^-34\n",
+"\n",
+"c=3*10^8\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"m=9.1*10^-31\n",
+"\n",
+"Ep=100*10^3*e//energy of photon\n",
+"\n",
+"lamp=((h*c)/Ep)//wavelength of photon\n",
+"\n",
+"lame=lamp//wavelength of electron\n",
+"\n",
+"v=h/(m*lame)\n",
+"\n",
+"KEe=0.5*m*(v^2)//kinetic energy of electron\n",
+"\n",
+"KEe=KEe/(1.6*10^-19)\n",
+"\n",
+"printf('kinetic energy of electron\n')\n",
+"\n",
+"printf('KEe=%.2f ev',KEe)"
+   ]
+   }
+],
+"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_U_Mukherji/12-Laser_Holography_And_Fibre_Optics.ipynb b/Engineering_Physics_by_U_Mukherji/12-Laser_Holography_And_Fibre_Optics.ipynb
new file mode 100644
index 0000000..8dc1477
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/12-Laser_Holography_And_Fibre_Optics.ipynb
@@ -0,0 +1,177 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 12: Laser Holography And Fibre Optics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.1: normalised_frequency_and_guided_modes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter12,Example12_1,pg 357\n",
+"\n",
+"n1=1.53//refractive index\n",
+"\n",
+"n2=1.5\n",
+"\n",
+"lam=1*10^-6//wavelength\n",
+"\n",
+"a=50*10^-6\n",
+"\n",
+"NA=sqrt((n1^2)-(n2^2))\n",
+"\n",
+"V=((2*%pi*a)*NA)/lam\n",
+"\n",
+"printf('normalised frequency\n')\n",
+"\n",
+"printf('V=%.2f ',V)\n",
+"\n",
+"M=(V^2)/2\n",
+"\n",
+"printf('\ntotal no. of guided mode\n')\n",
+"\n",
+"printf('M=%.2f',M)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.2: find_core_radius.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter12,Example12_2,pg 357\n",
+"\n",
+"lam=1*10^-6//wavelength\n",
+"\n",
+"n1=1.53\n",
+"\n",
+"n2=1.5\n",
+"\n",
+"NA=sqrt((n1^2)-(n2^2))\n",
+"\n",
+"a=(2.405*lam)/(2*%pi*NA)\n",
+"\n",
+"printf('core radius\n')\n",
+"\n",
+"printf('a=%.8f m',a)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.3: calculate_relative_change_in_core_cladding_RI.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter12,Example12_3,pg 357\n",
+"\n",
+"NA=0.5\n",
+"\n",
+"n1=1.54\n",
+"\n",
+"n2=sqrt((n1^2)-(NA^2))\n",
+"\n",
+"printf('refractive index of cladding\n')\n",
+"\n",
+"printf('n2=%.2f ',n2)\n",
+"\n",
+"n=(n1-n2)/n1//relative change in refractive index of core\n",
+"\n",
+"printf('\nrelative change refractive index of core\n')\n",
+"\n",
+"printf('n=%.2f ',n)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.4: find_cladding_RI_and_acceptance_angle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter12,Example12_4,pg 358\n",
+"\n",
+"NA=0.5\n",
+"\n",
+"n1=1.48\n",
+"\n",
+"n2=sqrt((n1^2)-(NA^2))\n",
+"\n",
+"printf('refractive index of cladding\n')\n",
+"\n",
+"printf('n2=%.2f ',n2)\n",
+"\n",
+"alpha=asin(NA)\n",
+"\n",
+"alpha=alpha*(180/%pi)\n",
+"\n",
+"printf('\nacceptance angle\n')\n",
+"\n",
+"printf('alpha=%.2f deg',alpha)"
+   ]
+   }
+],
+"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_U_Mukherji/13-Radioactivity_And_Nuclear_Reactions.ipynb b/Engineering_Physics_by_U_Mukherji/13-Radioactivity_And_Nuclear_Reactions.ipynb
new file mode 100644
index 0000000..688f608
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/13-Radioactivity_And_Nuclear_Reactions.ipynb
@@ -0,0 +1,263 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 13: Radioactivity And Nuclear Reactions"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.1: energy_of_incident_particle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter13,Example13_1,pg 391\n",
+"\n",
+"//xMy -> x-mass no., M-element, y-atomic no.\n",
+"\n",
+"M7Li3=7.018232//mass of 7li3 (amu)\n",
+"\n",
+"Malpha=4.003874//mass of alpha particle (amu)\n",
+"\n",
+"Mpr=1.008145//mass of proton (amu)\n",
+"\n",
+"//reaction:- 7li3 + 1H1-> 4He2 + 4He2\n",
+"\n",
+"delM=M7Li3+Mpr-2*Malpha//mass defect\n",
+"\n",
+"Q=delM*931//1 amu= 931 Mev\n",
+"\n",
+"Ey=9.15//K.E energy of product nucleus\n",
+"\n",
+"Ex=2*Ey-Q//K.E of incident particle\n",
+"\n",
+"printf('kinetic energy of incident proton\n')\n",
+"\n",
+"printf('Ex=%.2f Mev',Ex)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.2: power_of_explosio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter13,Example13_2,pg 391\n",
+"\n",
+"M235U=235//at.mass of 235U\n",
+"\n",
+"m=10^-3\n",
+"\n",
+"N=6.023*10^23\n",
+"\n",
+"Eperfi=200*10^6//energy per fission\n",
+"\n",
+"E=Eperfi*1.6*10^-19//energy per fission (in joules)\n",
+"\n",
+"T=10^-6\n",
+"\n",
+"A=M235U\n",
+"\n",
+"P=((m*N)/A)*(E/T)//power output\n",
+"\n",
+"printf('power of explosion\n')\n",
+"\n",
+"printf('P=%.2f watt',P)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.4: mass_of_uranium_consumed.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter13,Example13_4,pg 392\n",
+"\n",
+"n=0.4//efficiency\n",
+"\n",
+"N=6.023*10^23\n",
+"\n",
+"Eperfi=200*10^6//energy per fission\n",
+"\n",
+"E=Eperfi*1.6*10^-19\n",
+"\n",
+"P=100*10^6\n",
+"\n",
+"A=235\n",
+"\n",
+"T=24*60*60\n",
+"\n",
+"m=(P*A*T)/(n*N*E)\n",
+"\n",
+"printf('mass of 235U consumed/day\n')\n",
+"\n",
+"printf('m=%.2f gm',m)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.5: energy_liberated_per_reaction.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter13,Example13_5,pg 392\n",
+"\n",
+"M2H1=2.01474\n",
+"\n",
+"M3H1=3.01700\n",
+"\n",
+"M1n0=1.008986\n",
+"\n",
+"M4He2=4.003880\n",
+"\n",
+"//thermonuclear reaction in hydrogen bomb explosion \n",
+"\n",
+"//2H1 + 3H1 -> 4He2 + 1n0\n",
+"\n",
+"Mreac=M2H1+M3H1//mass of reactants\n",
+"\n",
+"Mprod=M4He2+M1n0//mass of products\n",
+"\n",
+"Q=Mreac-Mprod\n",
+"\n",
+"Q=Q*931//converting in Mev\n",
+"\n",
+"printf('energy/reaction\n')\n",
+"\n",
+"printf('Q=%.2f Mev',Q)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.6: calculate_binding_energy.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter13,Example13_6,pg 393\n",
+"\n",
+"M7Li3=7.01818\n",
+"\n",
+"M1H1=1.0081\n",
+"\n",
+"M1n0=1.009\n",
+"\n",
+"BEpernu=(1/7)*((3*M1H1)+(4*M1n0)-M7Li3)//binding energy per nucleon\n",
+"\n",
+"BEpernu=BEpernu*931//converting in Mev\n",
+"\n",
+"printf('binding energy per nucleon\n')\n",
+"\n",
+"printf('BE=%.2f Mev',BEpernu)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.7: calculate_power_output.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter13,Example13_7,pg 394\n",
+"\n",
+"m=10*10^3\n",
+"\n",
+"N=6.023*10^23\n",
+"\n",
+"Eperfi=200*10^6//energy per fission\n",
+"\n",
+"E=Eperfi*1.6*10^-19//energy in joules\n",
+"\n",
+"A=235\n",
+"\n",
+"T=24*60*60\n",
+"\n",
+"P=((m*N)/A)*(E/T)\n",
+"\n",
+"printf('power output\n')\n",
+"\n",
+"printf('P=%.2f watt',P)"
+   ]
+   }
+],
+"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_U_Mukherji/2-Thermoelectricity.ipynb b/Engineering_Physics_by_U_Mukherji/2-Thermoelectricity.ipynb
new file mode 100644
index 0000000..4fdafbb
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/2-Thermoelectricity.ipynb
@@ -0,0 +1,164 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 2: Thermoelectricity"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.1: find_out_inversion_temperature.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter-2,Example2_1,pg 54\n",
+"\n",
+"Tn=285\n",
+"\n",
+"Tc1=20\n",
+"\n",
+"Ti1=(2*Tn)-Tc1\n",
+"\n",
+"Tc2=-20\n",
+"\n",
+"Ti2=(2*Tn)-Tc2\n",
+"\n",
+"printf('higher temperature\n')\n",
+"\n",
+"printf('Ti1=%.f deg. C',Ti1)\n",
+"\n",
+"printf('\ntemperature of inversion\n')\n",
+"\n",
+"printf('Ti2=%.f deg. C',Ti2)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.2: thermo_emf_of_thermocouple.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter-2,Example2_2,pg 54\n",
+"\n",
+"aFe=16.65\n",
+"\n",
+"aAg=2.86\n",
+"\n",
+"bFe=-0.095\n",
+"\n",
+"bAg=0.017\n",
+"\n",
+"aFe_Ag=aFe-aAg\n",
+"\n",
+"bFe_Ag=bFe-bAg\n",
+"\n",
+"a=aFe_Ag\n",
+"\n",
+"b=bFe_Ag\n",
+"\n",
+"Tn=-(a/b)\n",
+"\n",
+"t=100\n",
+"\n",
+"EFe_Ag=(a*t)+0.5*(b*(t^2))\n",
+"\n",
+"printf('neutral temp. of Fe-Ag thermocouple\n')\n",
+"\n",
+"printf('Tn=%.3f deg. C',Tn)\n",
+"\n",
+"printf('\nthermo e.m.f of thermocouple\n')\n",
+"\n",
+"printf('EFe_Ag=%.f volts',EFe_Ag)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.3: emf_of_thermocouple.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter-2,Example2_3,pg 54\n",
+"\n",
+"//P=(dE/dt)Fe=a+b*t=1734-4.87*t\n",
+"\n",
+"//P=(dE/dt)Cu=a+b*t=136+0.95*t\n",
+"\n",
+"aFe_Pb=1734*10^-6\n",
+"\n",
+"aFe_Cu=(1734-136)*10^-6\n",
+"\n",
+"aCu_Pb=136*10^-6\n",
+"\n",
+"bFe_Pb=-4.87*10^-6\n",
+"\n",
+"bFe_Cu=(-4.87-0.95)*10^-6\n",
+"\n",
+"bCu_Pb=0.95*10^-6\n",
+"\n",
+"a=aFe_Cu\n",
+"\n",
+"b=bFe_Cu\n",
+"\n",
+"t=100\n",
+"\n",
+"EFe_Cu=(a*t)+0.5*(b*(t^2))\n",
+"\n",
+"printf('e.m.f of termocouple\n')\n",
+"\n",
+"printf('EFe_Cu=%.4f Volt',EFe_Cu)"
+   ]
+   }
+],
+"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_U_Mukherji/3-Thermionic_Emission.ipynb b/Engineering_Physics_by_U_Mukherji/3-Thermionic_Emission.ipynb
new file mode 100644
index 0000000..5371bed
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/3-Thermionic_Emission.ipynb
@@ -0,0 +1,111 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 3: Thermionic Emission"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.1: Richardson_Dushman_Equation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter-3,Example3_1,pg 67\n",
+"\n",
+"S=2*10^-6\n",
+"\n",
+"T=2000\n",
+"\n",
+"A=60.2*10^4\n",
+"\n",
+"b=52400//Q/K\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"I=A*S*(T^2)*(%e^(-(b/T)))\n",
+"\n",
+"J=A*(T^2)*(%e^(-(b/T)))\n",
+"\n",
+"no=J/e\n",
+"\n",
+"printf('maximum obtainable electronic emission current\n')\n",
+"\n",
+"disp(I)\n",
+"\n",
+"printf('\nemission current density\n')\n",
+"\n",
+"printf('J=%.3f A/m2',J)\n",
+"\n",
+"printf('\nno. of electrons emitted per unit area per sec.\n')\n",
+"\n",
+"disp(no)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.2: calculate_plate_voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter-3,Example3_2,pg 67\n",
+"\n",
+"Ip1=20*10^-3\n",
+"\n",
+"Ip2=30*10^-3\n",
+"\n",
+"Vp1=80\n",
+"\n",
+"//Ip=K*(Vp^(3/2))\n",
+"\n",
+"Vp2=((((Vp1)^(3/2))*Ip2)/Ip1)^(2/3)\n",
+"\n",
+"printf('plate voltage for 30mA current\n')\n",
+"\n",
+"printf('Vp2=%.2f volts',Vp2)"
+   ]
+   }
+],
+"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_U_Mukherji/4-Ultrasonic.ipynb b/Engineering_Physics_by_U_Mukherji/4-Ultrasonic.ipynb
new file mode 100644
index 0000000..ef12167
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/4-Ultrasonic.ipynb
@@ -0,0 +1,138 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 4: Ultrasonic"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.1: find_distance_between_two_ships.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter4,Example4_1,pg 84\n",
+"\n",
+"V1=343\n",
+"\n",
+"//S=V1*t1\n",
+"\n",
+"V2=1372\n",
+"\n",
+"//S=V2*t2\n",
+"\n",
+"dt=3//time difference\n",
+"\n",
+"S=((V1*V2)*(dt))/(V2-V1)\n",
+"\n",
+"printf('distance between two ships\n')\n",
+"\n",
+"printf('S=%.f m',S)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.2: calculate_depth_of_sea.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter4,Example4_2,pg 84\n",
+"\n",
+"V=1700\n",
+"\n",
+"t=0.65\n",
+"\n",
+"d=(V*t)/2\n",
+"\n",
+"n=0.07*10^6\n",
+"\n",
+"lam=V/n\n",
+"\n",
+"printf('depth of sea\n')\n",
+"\n",
+"printf('d=%.1f m',d)\n",
+"\n",
+"printf('\nwavelength of pulse\n')\n",
+"\n",
+"printf('lam=%.4f m',lam)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.3: calculate_natural_frequency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter4,Example4_3,pg 84\n",
+"\n",
+"P=1\n",
+"\n",
+"l=40*10^-3\n",
+"\n",
+"E=115*10^9\n",
+"\n",
+"D=7.25*10^3\n",
+"\n",
+"n=(P/(2*l))*sqrt(E/D)\n",
+"\n",
+"printf('natural frequency\n')\n",
+"\n",
+"printf('n=%.2f Hz',n)\n",
+"\n",
+"printf('\nfrequency of rod is more than audible range, rod cannot be used in magnetostriction oscillator\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_U_Mukherji/5-Acoustics.ipynb b/Engineering_Physics_by_U_Mukherji/5-Acoustics.ipynb
new file mode 100644
index 0000000..1867012
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/5-Acoustics.ipynb
@@ -0,0 +1,162 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 5: Acoustics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.1: find_absorption_coefficient.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter5,Example5_1,pg 97\n",
+"\n",
+"T1=1.5\n",
+"\n",
+"T2=1\n",
+"\n",
+"A=20\n",
+"\n",
+"V=10*8*6\n",
+"\n",
+"a=((0.161*V)/(2*A))*((1/T2)-(1/T1))\n",
+"\n",
+"printf('absorption coefficient\n')\n",
+"\n",
+"printf('a=%.3f Sabines',a)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.2: find_area_of_wall_covered_by_curtain.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter5,Example5_2,pg 97\n",
+"\n",
+"V=3000\n",
+"\n",
+"T1=3.5//reverberation time\n",
+"\n",
+"A=(0.161*V)/T1\n",
+"\n",
+"l=20\n",
+"\n",
+"b=15\n",
+"\n",
+"h=10\n",
+"\n",
+"S=2*((l*b)+(b*h)+(h*l))\n",
+"\n",
+"sum_a=A/S\n",
+"\n",
+"am=0.5\n",
+"\n",
+"a=0.106\n",
+"\n",
+"T2=2.5//reverberation time after cloth use\n",
+"\n",
+"S1=(((0.161*V)/(am-a))*((1/T2)-(1/T1)))\n",
+"\n",
+"printf('area of wall covered by curtain cloth\n')\n",
+"\n",
+"printf('S1=%.3f sq.m',S1)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.3: find_reverberation_time.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter5,Example5_3,pg 98\n",
+"\n",
+"V=1450\n",
+"\n",
+"A1=112*0.03//absorption due to plastered wall\n",
+"\n",
+"A2=130*0.06//absorption due to wooden floor\n",
+"\n",
+"A3=170*0.04//absorption due to plastd. celing\n",
+"\n",
+"A4=20*0.06//absorption due to wooden door\n",
+"\n",
+"A5=100*1//absorption due to cushioned chairs\n",
+"\n",
+"sum_as=A1+A2+A3+A4+A5\n",
+"\n",
+"T1=(0.161*V)/sum_as//reverberation time case-1\n",
+"\n",
+"T2=(0.161*V)/(sum_as+(60*4.7))//persons=60,A=4.7  case-2\n",
+"\n",
+"T3=(0.161*V)/(sum_as+(100*4.7))//seat cushioned=100 rev. case-3\n",
+"\n",
+"printf('rev. time for case-1\n')\n",
+"\n",
+"printf('T1=%.3f sec',T1)\n",
+"\n",
+"printf('\nrev. time for case-2\n')\n",
+"\n",
+"printf('T2=%.3f sec',T2)\n",
+"\n",
+"printf('\nrev. time for case-3\n')\n",
+"\n",
+"printf('T3=%.3f sec',T3)"
+   ]
+   }
+],
+"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_U_Mukherji/6-Semiconductors.ipynb b/Engineering_Physics_by_U_Mukherji/6-Semiconductors.ipynb
new file mode 100644
index 0000000..1a3bc87
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/6-Semiconductors.ipynb
@@ -0,0 +1,841 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 6: Semiconductors"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.10: Hall_Effect.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_10,pg 124\n",
+"\n",
+"Rhp=3.66*10^-4\n",
+"\n",
+"rho=8.93*10^-3\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"p=1/(Rhp*e)\n",
+"\n",
+"Uhp=Rhp/rho\n",
+"\n",
+"Bz=0.5\n",
+"\n",
+"theta=atan(Uhp*Bz)\n",
+"\n",
+"theta=theta*(180/%pi)\n",
+"\n",
+"printf('density of charge carrier\n')\n",
+"\n",
+"disp(p)\n",
+"\n",
+"printf('\nhall angle\n')\n",
+"\n",
+"printf('theta=%.2f deg.',theta)\n",
+"\n",
+"printf('\nhall mobility\n')\n",
+"\n",
+"printf('Uhp=%.4f m2/VS',Uhp)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.11: effect_of_external_impurity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_11,pg 124\n",
+"\n",
+"ni=2.5*10^13\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"un=3900\n",
+"\n",
+"up=1900\n",
+"\n",
+"sigin=ni*e*(un+up)//intrinsic conductivity\n",
+"\n",
+"//1 donor atom/10^8 Ge atom dropped\n",
+"\n",
+"rhoGe=4.42*10^22//no. of Ge atom/cc\n",
+"\n",
+"Nd=rhoGe/10^8\n",
+"\n",
+"sigex=Nd*e*un//extrinsic conductivity\n",
+"\n",
+"printf('extrinsic conductivity\n')\n",
+"\n",
+"printf('sigex=%.4f ohm cm',sigex)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.12: probability_of_electron_in_CB.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_12,pg 124\n",
+"\n",
+"//permeability of electron to be in C.B=F(Ec)\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"Eg=5.6\n",
+"\n",
+"Ef=Eg/2\n",
+"\n",
+"Ec=Eg\n",
+"\n",
+"K=1.38*10^-23\n",
+"\n",
+"T=27+273//converting in Kelvin\n",
+"\n",
+"KT=K*T\n",
+"\n",
+"KT=KT/e\n",
+"\n",
+"//e^(Ec-Ef/KT)>>1\n",
+"\n",
+"Fermi_F=e^((Ef-Ec)/KT)//fermi factor\n",
+"\n",
+"printf('probability of electron on CB\n')\n",
+"\n",
+"disp(Fermi_F)\n",
+"\n",
+"printf('\nit is infinite in negative direction for an insulator like diamond, so diamond cannot take part in conduction')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.13: Hall_Effect.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_13,pg 125\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"n=7*10^21\n",
+"\n",
+"ue=0.39\n",
+"\n",
+"V=10^-3\n",
+"\n",
+"A=10^-6\n",
+"\n",
+"L=10*10^-3\n",
+"\n",
+"I=(n*e*ue*V*A)/L\n",
+"\n",
+"Rhe=-(1/(n*e))\n",
+"\n",
+"Bz=0.2\n",
+"\n",
+"d=10^-3\n",
+"\n",
+"Vhe=(Rhe*I*Bz)/d\n",
+"\n",
+"printf('current through bar I=%.7f A\n',I)\n",
+"\n",
+"printf('\nhall coeff. Rhe=%.6f m3/c\n',Rhe)\n",
+"\n",
+"printf('\nhall voltage Vhe=%.8f volt\n',Vhe)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.14: find_forward_bias_current_flow.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_14,pg 136\n",
+"\n",
+"J2=0.2*10^-6\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"V=0.1\n",
+"\n",
+"K=1.38*10^-23\n",
+"\n",
+"T=300\n",
+"\n",
+"J=J2*(e^((e*V)/(K*T)))//as e^((e*v)/KT)>>1\n",
+"\n",
+"printf('forward bias current flow\n')\n",
+"\n",
+"disp(J)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.15: find_static_and_dynamic_resistance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_15,pg 148\n",
+"\n",
+"V1=1.4\n",
+"\n",
+"I1=60*10^-3\n",
+"\n",
+"V2=1.5\n",
+"\n",
+"I2=85*10^-3\n",
+"\n",
+"Rs1=V1/I1\n",
+"\n",
+"Rs2=V2/I2\n",
+"\n",
+"dV=V2-V1\n",
+"\n",
+"dI=I2-I1\n",
+"\n",
+"Rd=dV/dI\n",
+"\n",
+"printf('static resistance\n')\n",
+"\n",
+"printf('Rs1=%.2f ohm\n',Rs1)\n",
+"\n",
+"printf('Rs2=%.2f ohm\n',Rs2)\n",
+"\n",
+"printf('dynamic resistance\n')\n",
+"\n",
+"printf('Rd=%.2f ohm',Rd)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.16: find_alpha_and_beta.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_16,pg 148\n",
+"\n",
+"Ie=1*10^-3\n",
+"\n",
+"Ib=0.02*10^-3\n",
+"\n",
+"Ic=Ie-Ib\n",
+"\n",
+"B=Ic/Ib\n",
+"\n",
+"alpha=Ic/Ie\n",
+"\n",
+"printf('alpha=%.2f \n',alpha)\n",
+"\n",
+"printf('B=%.2f \n',B)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.17: find_leakage_current_Iceo.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_17,pg 148\n",
+"\n",
+"alpha=0.99\n",
+"\n",
+"Icbo=0.5*10^-6\n",
+"\n",
+"B=alpha/(1-alpha)\n",
+"\n",
+"Iceo=(1/(1-alpha))*Icbo\n",
+"\n",
+"printf('B=%.f \n',B)\n",
+"\n",
+"printf('Iceo=%.8f A',Iceo)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.18: find_alpha_and_beta.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_18,pg 148\n",
+"\n",
+"delIc=2.5*10^-3\n",
+"\n",
+"delIb=40*10^-6\n",
+"\n",
+"B=delIc/delIb\n",
+"\n",
+"alpha=B/(1+B)\n",
+"\n",
+"printf('alpha=%.5f\n',alpha)\n",
+"\n",
+"printf('B=%.2f',B)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.19: find_current_gain.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_19,pg 148\n",
+"\n",
+"Ie=1*10^-3\n",
+"\n",
+"Ib=0.04*10^-3\n",
+"\n",
+"Ic=Ie-Ib\n",
+"\n",
+"alpha=Ic/Ie\n",
+"\n",
+"printf('current gain\n')\n",
+"\n",
+"printf('alpha=%.2f',alpha)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.1: final_velocity_of_electron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_1,pg 121\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"V=1000\n",
+"\n",
+"m=9.1*10^-31\n",
+"\n",
+"v=sqrt((2*e*V)/m)\n",
+"\n",
+"printf('final velocity of electron\n')\n",
+"\n",
+"printf('v=%.f m/sec',v)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.20: find_base_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_20,pg 149\n",
+"\n",
+"V=1.5\n",
+"\n",
+"R=10^3\n",
+"\n",
+"Ic=V/R\n",
+"\n",
+"alpha=0.96\n",
+"\n",
+"Ie=Ic/alpha\n",
+"\n",
+"Ib=Ie-Ic\n",
+"\n",
+"printf('base current\n')\n",
+"\n",
+"printf('Ib=%.6f A',Ib)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.2: find_electric_field.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_2,pg 121\n",
+"\n",
+"Jc=1\n",
+"\n",
+"sig=5.8*10^7\n",
+"\n",
+"E=(Jc)/sig\n",
+"\n",
+"printf('electric field established\n')\n",
+"\n",
+"disp(E)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.3: electric_field_intensity_for_silver.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_3,pg 121\n",
+"\n",
+"vd=1*10^-3\n",
+"\n",
+"sig=6.17*10^7\n",
+"\n",
+"ue=0.0056\n",
+"\n",
+"rhoe=-(sig/ue)\n",
+"\n",
+"Jc1=-rhoe*vd\n",
+"\n",
+"E1=(Jc1)/sig\n",
+"\n",
+"I=80\n",
+"\n",
+"A=9*10^-6\n",
+"\n",
+"Jc2=I/A\n",
+"\n",
+"E2=Jc2/sig\n",
+"\n",
+"V=0.5*10^-3\n",
+"\n",
+"d=3*10^-3\n",
+"\n",
+"E3=V/d\n",
+"\n",
+"printf('E-field due to Jc1\n')\n",
+"\n",
+"printf('E1=%.6f V/m',E1)\n",
+"\n",
+"printf('\nE-field due to Jc2\n')\n",
+"\n",
+"printf('E2=%.6f V/m',E2)\n",
+"\n",
+"printf('\nE-field due to cube\n')\n",
+"\n",
+"printf('E3=%.6f V/m',E3)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.4: find_current_density_current_and_power_out.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_4,pg 122\n",
+"\n",
+"sig=3.82*10^7\n",
+"\n",
+"L=1000*12*2.54*10^-2//converting into m\n",
+"\n",
+"r=0.4*2.54*10^-2\n",
+"\n",
+"V=1.2\n",
+"\n",
+"Jc=sig*(V/L)\n",
+"\n",
+"A=3.14*(r^2)\n",
+"\n",
+"Ic=Jc*A\n",
+"\n",
+"P=Ic*V\n",
+"\n",
+"printf('current density\n')\n",
+"\n",
+"printf('Jc=%.f A/m2',Jc)\n",
+"\n",
+"printf('\ntotal current\n')\n",
+"\n",
+"printf('Ic=%.2f A',Ic)\n",
+"\n",
+"printf('\npower dissipation\n')\n",
+"\n",
+"printf('P=%.2f watt',P)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5: conductivity_due_to_holes_and_electrons.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_5,pg 122\n",
+"\n",
+"ni=2.5*10^19\n",
+"\n",
+"um=0.39\n",
+"\n",
+"up=0.19\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"L=6*10^-3\n",
+"\n",
+"R=120\n",
+"\n",
+"A=0.5*10^-6\n",
+"\n",
+"sigp=L/(R*A)\n",
+"\n",
+"p=sigp/(e*up)\n",
+"\n",
+"Na=p\n",
+"\n",
+"n=(ni^2)/Na\n",
+"\n",
+"sigm=n*e*um\n",
+"\n",
+"ratio=sigp/sigm\n",
+"\n",
+"printf('p-type impurity concentration\n')\n",
+"\n",
+"disp(p)\n",
+"\n",
+"printf('\nproportion of conductivity due to hole and electron\n')\n",
+"\n",
+"printf('ratio=%.f',ratio);printf(':1')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6: calculate_current_due_to_Ge_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_6,pg 123\n",
+"\n",
+"ni=2*10^19\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"up=0.17\n",
+"\n",
+"un=0.36\n",
+"\n",
+"V=2\n",
+"\n",
+"A=10^-4\n",
+"\n",
+"d=0.3*10^-3\n",
+"\n",
+"I=(ni*e*(up+un)*V*A)/d\n",
+"\n",
+"printf('current produced in Ge-plate\n')\n",
+"\n",
+"printf('I=%.4f A',I)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.7: find_intrinsic_carrier_density.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_7,pg 123\n",
+"\n",
+"rho=6.3*10^4\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"up=0.14\n",
+"\n",
+"un=0.05\n",
+"\n",
+"ni=1/(rho*e*(up+un))\n",
+"\n",
+"printf('intrinsic carrier concentration\n')\n",
+"\n",
+"disp(ni)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.8: Hall_Effect.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_8,pg 123\n",
+"\n",
+"L=10^-3\n",
+"\n",
+"R=1.5\n",
+"\n",
+"A=10^-6\n",
+"\n",
+"Ey=0.6\n",
+"\n",
+"w=10^-3\n",
+"\n",
+"d=10^-3\n",
+"\n",
+"I=120*10^-3\n",
+"\n",
+"Bz=0.05\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"sigp=L/(R*A)\n",
+"\n",
+"Vhp=Ey*w\n",
+"\n",
+"Rhp=(Vhp*d)/(I*Bz)\n",
+"\n",
+"Uhp=sigp*Rhp\n",
+"\n",
+"theta=atan(Uhp*Bz)\n",
+"\n",
+"theta=theta*(180/%pi)\n",
+"\n",
+"p=1/(Rhp*e)\n",
+"\n",
+"printf('hall voltage :Vhp=%.4f Volt\n',Vhp)\n",
+"\n",
+"printf('\nhall coeff. :Rhp=%.5f m3/e\n',Rhp)\n",
+"\n",
+"printf('\nhall mobility :Uhp=%.4f m2/VS\n',Uhp)\n",
+"\n",
+"printf('\nhall angle :theta=%.2f deg.\n',theta)\n",
+"\n",
+"printf('\ndensity of charge carrier\n')\n",
+"\n",
+"disp(p)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.9: concentration_of_holes_in_Si.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6,Example6_9,pg 123\n",
+"\n",
+"n=1.4*10^24\n",
+"\n",
+"ni=1.4*10^19\n",
+"\n",
+"Nd=n\n",
+"\n",
+"p=(ni^2)/Nd\n",
+"\n",
+"nbyp=n/p\n",
+"\n",
+"printf('electron-hole concentration ratio\n')\n",
+"\n",
+"disp(nbyp)"
+   ]
+   }
+],
+"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_U_Mukherji/8-Interference_Diffraction_And_Polarisation.ipynb b/Engineering_Physics_by_U_Mukherji/8-Interference_Diffraction_And_Polarisation.ipynb
new file mode 100644
index 0000000..877dd33
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/8-Interference_Diffraction_And_Polarisation.ipynb
@@ -0,0 +1,747 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 8: Interference Diffraction And Polarisation"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.10: calculate_change_in_thickness.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_10,pg 185\n",
+"\n",
+"//condition for dark fringe is 2*t=n*lam\n",
+"\n",
+"//refer to fig.(e) pg 185\n",
+"\n",
+"//but B=(lam/(2*alpha*u))\n",
+"\n",
+"//delt=alpha*x\n",
+"\n",
+"lam=6000*10^-8\n",
+"\n",
+"u=1.5\n",
+"\n",
+"delt=(10*lam)/(2*u)//alpha=lam/(2*B*u), B=x/10\n",
+"\n",
+"printf('difference t2-t1 from fig.\n')\n",
+"\n",
+"printf('delt=%.4f cm',delt)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.11: calculate_min_thickness_of_glass_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_11,pg 185\n",
+"\n",
+"//condition for dark is 2*u*t*cos(r)=n*lam\n",
+"\n",
+"lam=5890*10^-8\n",
+"\n",
+"u=1.5\n",
+"\n",
+"r=60*(%pi/180)\n",
+"\n",
+"//for n=1\n",
+"\n",
+"t=(lam)/(2*u*cos(r))\n",
+"\n",
+"printf('smallest thickness of glass plate\n')\n",
+"\n",
+"printf('t=%.8f cm',t)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.12: position_of_brightest_and_darkest_spot.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_12,pg 193\n",
+"\n",
+"//for brightest spot R1=sqrt(b*lam)\n",
+"\n",
+"R1=0.05\n",
+"\n",
+"lam=5*10^-5\n",
+"\n",
+"bb=(R1^2)/lam//brightest spot\n",
+"\n",
+"//for darkest spot\n",
+"\n",
+"bd=(R1^2)/(2*lam)//darkest spot\n",
+"\n",
+"printf('position of brightest spot\n')\n",
+"\n",
+"printf('b=%.2f cm',bb)\n",
+"\n",
+"printf('\nposition of darkest spot\n')\n",
+"\n",
+"printf('b=%.2f cm',bd)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.13: zone_plate_for_point_source.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_13,pg 193\n",
+"\n",
+"lam=6000*10^-10\n",
+"\n",
+"b1=30//for m=1\n",
+"\n",
+"b2=6//for m=2\n",
+"\n",
+"//(1/b)-(1/a)=(n*lam)/(R1^2), b=b1,b2\n",
+"\n",
+"//from b1,b2 equations \n",
+"\n",
+"a=((5*b2)-(3*b1))/2\n",
+"\n",
+"R1=sqrt(lam/((1/b1)-(1/a)))\n",
+"\n",
+"F1=(R1^2)/lam\n",
+"\n",
+"printf('distance of source from zone plate\n')\n",
+"\n",
+"printf('a=%.2f cm',a)\n",
+"\n",
+"printf('\nradius of 1st zone plate\n')\n",
+"\n",
+"printf('R1=%.4f cm',R1)\n",
+"\n",
+"printf('\nprincipal focal length\n')\n",
+"\n",
+"printf('F1=%.2f cm',F1)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.14: wavelength_of_spectral_line.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_14,pg 209\n",
+"\n",
+"grat=1/1250//transmission grating\n",
+"\n",
+"n=2\n",
+"\n",
+"theta=30*(%pi/180)//deviation angle\n",
+"\n",
+"//(a+b)sin(theta)=n*lam\n",
+"\n",
+"//grat=(a+b)\n",
+"\n",
+"lam=(grat*sin(theta))/n//wavelength of spectral line\n",
+"\n",
+"printf('wavelength of spectral line\n')\n",
+"\n",
+"printf('lam=%.6f cm',lam)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.15: max_orders_visible.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_15,pg 209\n",
+"\n",
+"lam=5893*10^-8\n",
+"\n",
+"grat=2.54/2540//converting into cm\n",
+"\n",
+"//(a+b)=grat\n",
+"\n",
+"//(a+b)sin(theta)=n*lam\n",
+"\n",
+"//n=nmax, if sin(theta)=1\n",
+"\n",
+"nmax=(grat/lam)\n",
+"\n",
+"printf('maximum order\n')\n",
+"\n",
+"printf('nmax=%.2f ',nmax)\n",
+"\n",
+"printf('so maximum order=16\n')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.16: linear_separation_of_Na_lines.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_16,pg 209\n",
+"\n",
+"n=2\n",
+"\n",
+"grat=1/5000//transmission grating\n",
+"\n",
+"lam=5893*10^-8\n",
+"\n",
+"dtheta=(2.5*3.14)/(180*60)//change in angular displacement(in radian)\n",
+"\n",
+"//(a+b)=grat\n",
+"\n",
+"//dlam=((a+b)cos(theta)/n)dtheta\n",
+"\n",
+"cos(theta)=sqrt(1-(((n*lam)/grat)^2))\n",
+"\n",
+"dlam=(dtheta*grat*cos(theta))/n//difference in wavelength\n",
+"\n",
+"f=30//focal length\n",
+"\n",
+"dl=f*dtheta//linear separation\n",
+"\n",
+"printf('difference between two yellow lines (in cm)\n')\n",
+"\n",
+"disp(dlam)\n",
+"\n",
+"printf('\nlinear separation\n')\n",
+"\n",
+"printf('dl=%.4f cm',dl)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.17: linear_separation_of_spectra_lines.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_17,pg 210\n",
+"\n",
+"grat=1/6000\n",
+"\n",
+"f=30\n",
+"\n",
+"n=2\n",
+"\n",
+"lam1=5770*10^-8\n",
+"\n",
+"lam2=5460*10^-8\n",
+"\n",
+"dlam=lam1-lam2\n",
+"\n",
+"lam=lam2\n",
+"\n",
+"cos(theta)=sqrt(1-(((n*lam)/grat)^2))\n",
+"\n",
+"dl=((n*f)/(grat*cos(theta)))*dlam\n",
+"\n",
+"printf('linear separation of two spectral lines\n')\n",
+"\n",
+"printf('dl=%.4f cm',dl)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.18: calculate_lines_per_cm_in_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_18,pg 210\n",
+"\n",
+"//nth order of lam1 is superimposed on (n+1)th order of lam2 for theta=30\n",
+"\n",
+"//(a+b)sin(30)=n*5400*10^-8=(n+1)*4050*10^-8\n",
+"\n",
+"lam1=5400*10^-8\n",
+"\n",
+"lam2=4050*10^-8\n",
+"\n",
+"n=(lam2/(lam1-lam2))\n",
+"\n",
+"theta=30*(%pi/180)\n",
+"\n",
+"N=sin(theta)/(n*lam1)\n",
+"\n",
+"printf('lines/cm in grating\n')\n",
+"\n",
+"printf('N=%.2f lines/cm',N)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.1: distance_of_fringe_from_wedge.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_1,pg 180\n",
+"\n",
+"alpha=0.01\n",
+"\n",
+"n=10\n",
+"\n",
+"lam=6000*10^-8\n",
+"\n",
+"u=1.5\n",
+"\n",
+"//for dark fringe 2*u*t*cos(alpha)=n*lam\n",
+"\n",
+"//t=xtan(alpha)\n",
+"\n",
+"//2*u*x*sin(alpha)=2*u*x*alpha=n*lam ->alpha is small, sin(alpha)=alpha\n",
+"\n",
+"x=(n*lam)/(2*u*alpha)\n",
+"\n",
+"printf('distance of 10th fringe from edge of wedge\n')\n",
+"\n",
+"printf('x=%.2f cm',x)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.2: light_reflected_in_visible_spectrum.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_2,pg 181\n",
+"\n",
+"//for constructive interference of reflected light\n",
+"\n",
+"//2*u*t*cos(r)=(2*n+1)(lam/2), where n=0,1,2,3\n",
+"\n",
+"//for normal incidence\n",
+"\n",
+"//r=0, cos(r)=1\n",
+"\n",
+"t=5*10^-5\n",
+"\n",
+"u=1.33\n",
+"\n",
+"//for n=0 lam=lam1\n",
+"\n",
+"lam1=4*u*t\n",
+"\n",
+"//for n=1 lam=lam2\n",
+"\n",
+"lam2=4*u*t*(1/3)\n",
+"\n",
+"//for n=2 lam=lam3\n",
+"\n",
+"lam3=4*u*t*(1/5)\n",
+"\n",
+"//for n=3 lam=lam4\n",
+"\n",
+"lam4=4*u*t*(1/7)\n",
+"\n",
+"printf('wavelength that is strongly reflected in visible spectrum\n')\n",
+"\n",
+"disp(lam3)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.3: radius_of_50th_dark_ring.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_3,pg 181\n",
+"\n",
+"n=10\n",
+"\n",
+"D10=0.5\n",
+"\n",
+"lam=5000*10^-8\n",
+"\n",
+"R=(D10^2)/(4*n*lam)\n",
+"\n",
+"D50=sqrt(4*50*R*lam)\n",
+"\n",
+"r50=D50/2\n",
+"\n",
+"printf('radius of 50th dark ring\n')\n",
+"\n",
+"printf('r50=%.2f cm',r50)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.4: thickness_of_film.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_4,pg 182\n",
+"\n",
+"i=45*(%pi/180)\n",
+"\n",
+"u=1.33\n",
+"\n",
+"r=asin(sin(i)/u)\n",
+"\n",
+"r=r*(180/%pi)\n",
+"\n",
+"//for bright fringe 2*u*t*cos(r)=(2*n+1)(lam/2)\n",
+"\n",
+"//for minimum thickness n=0\n",
+"\n",
+"lam=5000*10^-8\n",
+"\n",
+"t=lam/(4*u*t*cos(r))\n",
+"\n",
+"printf('min. thickness of film\n')\n",
+"\n",
+"disp(t)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.5: find_RI_of_oil.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_5,pg 182\n",
+"\n",
+"//since both reflections occur at surface of denser medium\n",
+"\n",
+"//condition for brightness for min thickness, n=1\n",
+"\n",
+"//for normal incidence r=0, cos(r)=1\n",
+"\n",
+"lam=5500*10^-8\n",
+"\n",
+"V=0.2\n",
+"\n",
+"A=100*100//converting into cm2\n",
+"\n",
+"t=V/A\n",
+"\n",
+"u=lam/(2*t)\n",
+"\n",
+"printf('RI of oil\n')\n",
+"\n",
+"printf('u=%.2f',u)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.6: change_in_film_thickness.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_6,pg 183\n",
+"\n",
+"lam=6300*10^-10\n",
+"\n",
+"u=1.5\n",
+"\n",
+"//condition for dark 2*u*t=n*lam\n",
+"\n",
+"//condition for bright 2*u*t=(2*n-1)(lam/2)\n",
+"\n",
+"//when t=0 n=0 order dark band will come and at edge 10th bright band will come \n",
+"\n",
+"n=10\n",
+"\n",
+"t=(((2*n)-1)*(lam))/(4*u)\n",
+"\n",
+"printf('thickness of air film\n')\n",
+"\n",
+"printf('t=%.12f cm',t)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.7: thickness_of_layer.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_7,pg 183\n",
+"\n",
+"ug=1.5\n",
+"\n",
+"uo=1.3\n",
+"\n",
+"//here reflection occurs both time at surface of denser medium\n",
+"\n",
+"//condition for distructive interference in reflected side\n",
+"\n",
+"//2*u*t*cos(r)=(2*n-1)(lam1/2), for nth min.\n",
+"\n",
+"r=0\n",
+"\n",
+"//for nth min.\n",
+"\n",
+"//2*u*t=(2*n+1)(lam1/2), n=0,1,2,3\n",
+"\n",
+"//for (n+1)th min.\n",
+"\n",
+"////2*u*t=(2*(n+1)+1)(lam2/2), n=0,1,2,3\n",
+"\n",
+"lam1=7000*10^-10\n",
+"\n",
+"lam2=5000*10^-10\n",
+"\n",
+"//from eq. of nth and (n+1)th min.\n",
+"\n",
+"t=(2/(4*uo))*((lam1*lam2)/(lam1-lam2))\n",
+"\n",
+"printf('thickness of layer\n')\n",
+"\n",
+"printf('t=%.12f m',t)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.8: calculate_RI_of_liquid.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_8,pg 184\n",
+"\n",
+"Dn=1.40\n",
+"\n",
+"D=1.27\n",
+"\n",
+"//when u=1\n",
+"\n",
+"//(Dn^2)=4*n*lam*R=(1.40^2)\n",
+"\n",
+"//when u=u1\n",
+"\n",
+"//(D^2)=(4*n*lam*R)/u1=(1.27^2)\n",
+"\n",
+"//from above eqn's\n",
+"\n",
+"u1=((Dn^2)/(D^2))\n",
+"\n",
+"printf('RI of liquid\n')\n",
+"\n",
+"printf('u=%.2f',u1)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.9: calculate_wavelength_of_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter8,Example8_9,pg 184\n",
+"\n",
+"alpha=((%pi*10)/(60*60*180))//converting into radian\n",
+"\n",
+"B=0.5//fringe width\n",
+"\n",
+"u=1.4\n",
+"\n",
+"lam=2*B*alpha*u\n",
+"\n",
+"printf('wavelength of light used\n')\n",
+"\n",
+"printf('lam=%.12f m',lam)"
+   ]
+   }
+],
+"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_U_Mukherji/9-X_Rays.ipynb b/Engineering_Physics_by_U_Mukherji/9-X_Rays.ipynb
new file mode 100644
index 0000000..2b48f75
--- /dev/null
+++ b/Engineering_Physics_by_U_Mukherji/9-X_Rays.ipynb
@@ -0,0 +1,388 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 9: X Rays"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.1: highest_order_of_reflectio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_1,pg 237\n",
+"\n",
+"d=4.255*10^-10\n",
+"\n",
+"lam=1.549*10^-10//wavelength of K-copper line\n",
+"\n",
+"n=1//theta is smallest when n=1\n",
+"\n",
+"theta=asin(lam/(2*d))//glancing angle\n",
+"\n",
+"theta=theta*(180/%pi)\n",
+"\n",
+"//max value of sin(theta)=1\n",
+"\n",
+"//for highest order\n",
+"\n",
+"nmax=((2*d)/lam)//highest bragg's order\n",
+"\n",
+"printf('smallest glancing angle\n')\n",
+"\n",
+"printf('theta=%.2f deg.',theta)\n",
+"\n",
+"printf('\nmaximum order of reflection\n')\n",
+"\n",
+"printf('nmax=%.2f',nmax)\n",
+"\n",
+"printf('\nsince fraction is meaningless for order nmax=5')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2: find_plancks_constant.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_2,pg 237\n",
+"\n",
+"V=60*10^3\n",
+"\n",
+"c=3*10^8\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"lam=0.194*10^-10//min. wavelength of x-rays\n",
+"\n",
+"h=(lam*e*V)/c\n",
+"\n",
+"printf('plancks constant\n')\n",
+"\n",
+"disp(h)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.3: find_wavelength_and_maximum_order_of_reflection.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_3,pg 238\n",
+"\n",
+"//for 110 plane\n",
+"\n",
+"a=3*10^-10//lattice parameter\n",
+"\n",
+"d=(a/sqrt(2))//d110=(a/sqrt((1^2)+(1^2)+0))\n",
+"\n",
+"theta=12.5*(%pi/180)//glancing angle\n",
+"\n",
+"n=1\n",
+"\n",
+"lam=2*d*sin(theta)//wavelength of x-ray\n",
+"\n",
+"nmax=((2*d)/lam)//highest order\n",
+"\n",
+"printf('wavelength of x-ray beam\n')\n",
+"\n",
+"disp(lam)\n",
+"\n",
+"printf('\nhighest braggs order\n')\n",
+"\n",
+"printf('nmax=%.2f',nmax)\n",
+"\n",
+"printf('\nfraction is meaningless so nmax=4')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.4: find_plancks_constant.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_4,pg 238\n",
+"\n",
+"d=2.81*10^-10\n",
+"\n",
+"theta=14*(%pi/180)//glancing angle\n",
+"\n",
+"lam=2*d*sin(theta)//min. wavelength\n",
+"\n",
+"e=1.6*10^-19\n",
+"\n",
+"V=9100\n",
+"\n",
+"c=3*10^8\n",
+"\n",
+"h=(lam*e*V)/c\n",
+"\n",
+"printf('plancks constant\n')\n",
+"\n",
+"disp(h)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.5: find_wavelength_of_line_A.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_5,pg 238\n",
+"\n",
+"//for line A-> 2*d*sin(thetaA)=lamA(n=1)\n",
+"\n",
+"thetaA=30*(%pi/180)//glancing angle for line A\n",
+"\n",
+"//for line B-> 2*d*sin(thetaB)=3*lamB(n=3)\n",
+"\n",
+"thetaB=60*(%pi/180)\n",
+"\n",
+"lamB=0.97*10^-10\n",
+"\n",
+"d=(3*lamB)/(2*sin(thetaB))\n",
+"\n",
+"lamA=2*d*sin(thetaA)//wavelength of line A\n",
+"\n",
+"printf('wavelength of line A\n')\n",
+"\n",
+"disp(lamA)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.6: find_wavelength_of_x_rays.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_6,pg 239\n",
+"\n",
+"a=3.615*10^-10\n",
+"\n",
+"d111=a/sqrt(1+1+1)//for 111 plane \n",
+"\n",
+"theta=21.7*(%pi/180)//converting into radian\n",
+"\n",
+"lam=2*d111*sin(theta)\n",
+"\n",
+"printf('wavelength of X-rays\n')\n",
+"\n",
+"disp(lam)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.7: find_min_wavelength_and_glancing_angle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_7,pg 239\n",
+"\n",
+"V=50*10^3\n",
+"\n",
+"lam=(12400/V)*10^-10\n",
+"\n",
+"n=4//FCC crystal\n",
+"\n",
+"m=74.6\n",
+"\n",
+"N=6.022*10^26\n",
+"\n",
+"rho=1.99*10^3\n",
+"\n",
+"a=(((n*m)/(N*rho))^(1/3))\n",
+"\n",
+"//for kcl ionic crystal\n",
+"\n",
+"d=a/2\n",
+"\n",
+"theta=asin(lam/(2*d))\n",
+"\n",
+"theta=theta*(180/%pi)\n",
+"\n",
+"printf('min. wavelength of spectrum from tube\n')\n",
+"\n",
+"disp(lam)\n",
+"\n",
+"printf('glancing angle for that wavelength\n')\n",
+"\n",
+"printf('theta=%.2f deg.',theta)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.8: identify_type_of_crystal.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_8,pg 239\n",
+"\n",
+"//from bragg's law\n",
+"\n",
+"//2*d*sin(theta)=n*lam\n",
+"\n",
+"n=1\n",
+"\n",
+"theta1=5.4*(%pi/180)\n",
+"\n",
+"theta2=7.6*(%pi/180)\n",
+"\n",
+"theta3=9.4*(%pi/180)\n",
+"\n",
+"d100=lam/2*sin(theta1)\n",
+"\n",
+"d110=lam/2*sin(theta2)\n",
+"\n",
+"d111=lam/2*sin(theta3)\n",
+"\n",
+"printf('ratio of interplannar spacing \n(1/d100):(1/d110):(1/d111)=')\n",
+"\n",
+"printf('%.2f:',sin(theta1));printf('%.2f:',sin(theta2));printf('%.2f',sin(theta3));\n",
+"\n",
+"printf('\nas ratio (1/d100):(1/d110):(1/d111)=1:sqrt(2):sqrt(3)this relation is valid for simple cubic crystal therefore, this is a SCC crystal')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.9: find_interplannar_spacing.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter9,Example9_9,pg 240\n",
+"\n",
+"lam=0.58*10^-10\n",
+"\n",
+"theta1=6.5*(%pi/180)\n",
+"\n",
+"theta2=9.15*(%pi/180)\n",
+"\n",
+"theta3=13*(%pi/180)\n",
+"\n",
+"//from bragg's law\n",
+"\n",
+"d1=lam/(2*sin(theta1))*10^10\n",
+"\n",
+"d2=lam/(2*sin(theta2))*10^10\n",
+"\n",
+"d3=lam/(2*sin(theta3))*10^10\n",
+"\n",
+"printf('interplannar spacing of crystal\n')\n",
+"\n",
+"printf('%.2f:',d1);printf('%.2f:',d2);printf('%.2f',d3);"
+   ]
+   }
+],
+"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
+}