initial commit / add all books

121 files changed, 1961 insertions, 0 deletions

diff --git a/3768/CH1/EX1.1/Ex1_1.sce b/3768/CH1/EX1.1/Ex1_1.sce
new file mode 100644
index 000000000..10e8461e2
--- /dev/null
+++ b/3768/CH1/EX1.1/Ex1_1.sce
@@ -0,0 +1,21 @@
+//Example number 1.1, Page number 10
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;      //charge(coulomb)
+epsilon0=8.85*10**-12;   
+r0=23.6*10**-10;    //equilibrium distance(m)
+I=5.14;    //ionisation energy(eV)
+EA=3.65;   //electron affinity(eV)
+N=8;     //born constant
+
+//Calculation
+x=1-(1/N);
+V=(e**2)*x/(4*e*%pi*epsilon0*r0);   //potential(V)
+E=I-EA;        //net energy(eV)
+BE=(V*10)-E;        //bond energy(eV)
+
+//Result
+printf( "bond energy = %.2f eV",BE)
+
diff --git a/3768/CH1/EX1.2/Ex1_2.sce b/3768/CH1/EX1.2/Ex1_2.sce
new file mode 100644
index 000000000..bff75feb7
--- /dev/null
+++ b/3768/CH1/EX1.2/Ex1_2.sce
@@ -0,0 +1,18 @@
+//Example number 1.2, Page number 10
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;      //charge(coulomb)
+epsilon0=8.85*10**-12;   
+r0=0.41*10**-3;    //equilibrium distance(m)
+A=1.76;      //madelung constant
+n=0.5;       //repulsive exponent value
+
+//Calculation
+Beta=72*%pi*epsilon0*r0**4/(A*e**2*(n-1));    //compressibility
+
+//Result
+printf( "compressibility =  %.4e",Beta)
+//answer in the book is wrong
diff --git a/3768/CH1/EX1.3/Ex1_3.sce b/3768/CH1/EX1.3/Ex1_3.sce
new file mode 100644
index 000000000..1eb887c55
--- /dev/null
+++ b/3768/CH1/EX1.3/Ex1_3.sce
@@ -0,0 +1,21 @@
+//Example number 1.3, Page number 10
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;      //charge(coulomb)
+epsilon0=8.85*10**-12;   
+r0=0.314*10**-9;    //equilibrium distance(m)
+A=1.75;      //madelung constant
+N=5.77;     //born constant
+I=4.1;    //ionisation energy(eV)
+EA=3.6;   //electron affinity(eV)
+
+//Calculation
+V=-A*e**2*((N-1)/N)/(4*e*%pi*epsilon0*r0);
+PE=V/2;    //potential energy per ion(eV)
+x=(I-EA)/2;
+CE=PE+x;   //cohesive energy(eV)
+
+//Result
+printf( "cohesive energy is = %.3f eV",CE)
diff --git a/3768/CH1/EX1.4/Ex1_4.sce b/3768/CH1/EX1.4/Ex1_4.sce
new file mode 100644
index 000000000..34a5d0701
--- /dev/null
+++ b/3768/CH1/EX1.4/Ex1_4.sce
@@ -0,0 +1,19 @@
+//Example number 1.4, Page number 11
+clc;clear;
+close;
+
+//Variable declaration    
+N=6.02*10**26;           //Avagadro Number
+e=1.6*10**-19;      //charge(coulomb)
+epsilon0=8.85*10**-12;   
+r0=0.324*10**-9;    //equilibrium distance(m)
+A=1.75;      //madelung constant
+n=8.5;       //repulsive exponent value
+
+//Calculations
+U0=(A*e/(4*%pi*epsilon0*r0))*(1-1/n);     
+U=U0*N*e/10**3;      //binding energy(kJ/kmol)
+
+//Result
+printf( "binding energy is %.1e kJ/mol",U)
+//answer in the book is wrong
diff --git a/3768/CH1/EX1.5/Ex1_5.sce b/3768/CH1/EX1.5/Ex1_5.sce
new file mode 100644
index 000000000..5830eab3b
--- /dev/null
+++ b/3768/CH1/EX1.5/Ex1_5.sce
@@ -0,0 +1,20 @@
+//Example number 1.5, Page number 11
+clc;clear;
+close;
+
+//Variable declaration
+rCs=0.165*10**-9;    //radius(m)
+rCl=0.181*10**-9;    //radius(m)
+MCs=133;    //atomic weight
+MCl=35.5;   //atomic weight
+N=6.02*10**26;           //Avagadro Number
+
+//Calculation
+a=2*(rCl+rCs)/sqrt(3);     //lattice constant(m)
+M=(MCs+MCl)/N;       //mass of 1 molecule(kg)
+V=a**3;    //volume of unit cell(m**3)
+rho=M/V;    //density of CsCl(kg/m**3)
+
+//Result
+printf( "density of CsCl is %.3e kg/m**3",rho)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH1/EX1.6/Ex1_6.sce b/3768/CH1/EX1.6/Ex1_6.sce
new file mode 100644
index 000000000..b8c17811b
--- /dev/null
+++ b/3768/CH1/EX1.6/Ex1_6.sce
@@ -0,0 +1,15 @@
+//Example number 1.6, Page number 12
+
+clc;clear;
+close;
+
+//Variable declaration
+dm=1.98*(10**-29)*(1/3);      //dipole moment
+l=0.92*10**-10;        //bond length(m)
+
+//Calculation
+ec=dm/l;        //effective charge(coulomb)
+
+//Result
+printf( "effective charge is %.1e Coulomb",ec)
+//answer given in the book is wrong
diff --git a/3768/CH1/EX1.7/Ex1_7.sce b/3768/CH1/EX1.7/Ex1_7.sce
new file mode 100644
index 000000000..ced71bc2e
--- /dev/null
+++ b/3768/CH1/EX1.7/Ex1_7.sce
@@ -0,0 +1,19 @@
+//Example number 1.7, Page number 12
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;      //charge(coulomb)
+epsilon0=8.85*10**-12;   
+r=0.5*10**-9;    //distance(m)
+I=5;    //ionisation energy(eV)
+E=4;   //electron affinity(eV)
+
+//Calculation
+C=e**2/(4*%pi*epsilon0*e*r);    //coulomb energy(eV)
+Er=I-E-C;    //energy required(eV)
+
+//Result
+printf( "energy required is %.1f eV",Er)
+
diff --git a/3768/CH1/EX1.9/Ex1_9.sce b/3768/CH1/EX1.9/Ex1_9.sce
new file mode 100644
index 000000000..9abfa6f84
--- /dev/null
+++ b/3768/CH1/EX1.9/Ex1_9.sce
@@ -0,0 +1,16 @@
+//Example number 1.9, Page number 13
+
+clc;clear;
+close;
+
+//Variable declaration
+a=7.68*10**-29;     
+r0=2.5*10**-10;    //radius(m)
+
+//Calculation
+b=a*(r0**8)/9;
+y=((-2*a*r0**8)+(90*b))/r0**11;    
+E=y/r0/10**9;           //young's modulus(GPa)
+
+//Result
+printf( "young''s modulus is %d GPa",E)
diff --git a/3768/CH10/EX10.1/Ex10_1.sce b/3768/CH10/EX10.1/Ex10_1.sce
new file mode 100644
index 000000000..d45d8310b
--- /dev/null
+++ b/3768/CH10/EX10.1/Ex10_1.sce
@@ -0,0 +1,13 @@
+//Example number 10.1, Page number 224
+
+clc;clear;
+close;
+
+//Variable declaration
+T=5;     //temperature(K)
+Tc=7.2;   //critical temperature(K)
+H0=6.5*10**3;   //critical magnetic field(A/m)
+//Calculation
+Hc=H0*(1-(T/Tc)**2);    //critical field(A/m)
+//Result
+printf("critical field is %.3e A/m",Hc)
diff --git a/3768/CH10/EX10.10/Ex10_10.sce b/3768/CH10/EX10.10/Ex10_10.sce
new file mode 100644
index 000000000..e67110c2c
--- /dev/null
+++ b/3768/CH10/EX10.10/Ex10_10.sce
@@ -0,0 +1,14 @@
+//Example number 10.10, Page number 227
+
+clc;clear;
+close;
+
+//Variable declaration
+Hc=6*10**5;    //critical magnetic field(A/m)
+Tc=8.7;     //critical temperature(K)
+H0=3*10**6;   //critical magnetic field(A/m)
+//Calculation
+T=Tc*sqrt(1-(Hc/H0));     //maximum critical temperature(K)
+//Result
+printf("maximum critical temperature is %.3f K",T)
+//answer given in the book is wrong
diff --git a/3768/CH10/EX10.2/Ex10_2.sce b/3768/CH10/EX10.2/Ex10_2.sce
new file mode 100644
index 000000000..116db8061
--- /dev/null
+++ b/3768/CH10/EX10.2/Ex10_2.sce
@@ -0,0 +1,13 @@
+//Example number 10.2, Page number 225
+
+clc;clear;
+close;
+
+//Variable declaration
+T=2.5;     //temperature(K)
+Tc=3.5;   //critical temperature(K)
+H0=3.2*10**3;   //critical magnetic field(A/m)
+//Calculation
+Hc=H0*(1-(T/Tc)**2);    //critical field(A/m)
+//Result
+printf("critical field is %.3e A/m",Hc)
diff --git a/3768/CH10/EX10.3/Ex10_3.sce b/3768/CH10/EX10.3/Ex10_3.sce
new file mode 100644
index 000000000..ff8458ab5
--- /dev/null
+++ b/3768/CH10/EX10.3/Ex10_3.sce
@@ -0,0 +1,14 @@
+//Example number 10.3, Page number 225
+
+clc;clear;
+close;
+
+//Variable declaration
+Hc=5*10**3;    //critical magnetic field(A/m)
+T=6;     //temperature(K)
+H0=2*10**4;   //critical magnetic field(A/m)
+//Calculation
+Tc=T/sqrt(1-(Hc/H0));     //critical temperature(K)
+//Result
+printf("critical temperature is %.3f K",Tc)
+//answer given in the book is wrong
diff --git a/3768/CH10/EX10.4/Ex10_4.sce b/3768/CH10/EX10.4/Ex10_4.sce
new file mode 100644
index 000000000..c16d259c6
--- /dev/null
+++ b/3768/CH10/EX10.4/Ex10_4.sce
@@ -0,0 +1,13 @@
+//Example number 10.4, Page number 225
+
+clc;clear;
+close;
+
+//Variable declaration
+Hc=2*10**3;    //critical magnetic field(A/m)
+r=0.02;    //radius(m)
+//Calculation
+Ic=2*%pi*r*Hc;     //critical current(amp)
+//Result
+printf("critical current is %.1f A",Ic)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH10/EX10.5/Ex10_5.sce b/3768/CH10/EX10.5/Ex10_5.sce
new file mode 100644
index 000000000..ad2984b66
--- /dev/null
+++ b/3768/CH10/EX10.5/Ex10_5.sce
@@ -0,0 +1,13 @@
+//Example number 10.5, Page number 225
+
+clc;clear;
+close;
+
+//Variable declaration
+T1=5;     //temperature(K)
+T2=5.1;     //temperature(K)
+M1=199.5;   //isotopic mass(amu)
+//Calculation
+M2=M1*(T1/T2)**2;    //isotopic mass(amu)
+//Result
+printf("isotopic mass is %.2f a.m.u.",M2)
diff --git a/3768/CH10/EX10.6/Ex10_6.sce b/3768/CH10/EX10.6/Ex10_6.sce
new file mode 100644
index 000000000..b382321b6
--- /dev/null
+++ b/3768/CH10/EX10.6/Ex10_6.sce
@@ -0,0 +1,17 @@
+//Example number 10.6, Page number 226
+
+clc;clear;
+close;
+
+//Variable declaration
+T=5;     //temperature(K)
+Tc=8;   //critical temperature(K)
+H0=5*10**4;   //critical magnetic field(A/m)
+r=1.5*10**-3;    //radius(m)
+//Calculation
+Hc=H0*(1-(T/Tc)**2);    //critical field(A/m)
+Ic=2*%pi*r*Hc;     //critical current(amp)
+//Result
+printf("critical field is %.4e A/m",Hc)
+printf("\n critical current is %.3f A",Ic)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH10/EX10.7/Ex10_7.sce b/3768/CH10/EX10.7/Ex10_7.sce
new file mode 100644
index 000000000..35c1aec11
--- /dev/null
+++ b/3768/CH10/EX10.7/Ex10_7.sce
@@ -0,0 +1,13 @@
+//Example number 10.7, Page number 226
+
+clc;clear;
+close;
+
+//Variable declaration
+Tc1=4.185;     //critical temperature(K)
+M1=199.5;   //isotopic mass(amu)
+M2=203.4;   //isotopic mass(amu)
+//Calculation
+Tc2=Tc1*sqrt(M1/M2);      //critical temperature(K)
+//Result
+printf("critical temperature is %.4f K",Tc2)
diff --git a/3768/CH10/EX10.8/Ex10_8.sce b/3768/CH10/EX10.8/Ex10_8.sce
new file mode 100644
index 000000000..6c49ca199
--- /dev/null
+++ b/3768/CH10/EX10.8/Ex10_8.sce
@@ -0,0 +1,13 @@
+//Example number 10.8, Page number 226
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;    //charge(c)
+h=6.626*10**-36;   //plank constant
+V=8.5*10**-6;    //voltage(V)
+//Calculation
+new=2*e*V/h;    //frequency(Hz)
+//Result
+printf("frequency is %.3e Hz",new)
diff --git a/3768/CH10/EX10.9/Ex10_9.sce b/3768/CH10/EX10.9/Ex10_9.sce
new file mode 100644
index 000000000..f6597a8d3
--- /dev/null
+++ b/3768/CH10/EX10.9/Ex10_9.sce
@@ -0,0 +1,13 @@
+//Example number 10.9, Page number 227
+
+clc;clear;
+close;
+
+//Variable declaration
+Tc1=5;     //critical temperature(K)
+P1=1;   //pressure(mm)
+P2=6;   //pressure(mm)
+//Calculation
+Tc2=Tc1*P2/P1;      //critical temperature(K)
+//Result
+printf("critical temperature is %.f K",Tc2)
diff --git a/3768/CH11/EX11.1/Ex11_1.sce b/3768/CH11/EX11.1/Ex11_1.sce
new file mode 100644
index 000000000..a4b76db19
--- /dev/null
+++ b/3768/CH11/EX11.1/Ex11_1.sce
@@ -0,0 +1,16 @@
+//Example number 11.1, Page number 246
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;     //charge(coulomb)
+v=3*10**3;   //velocity of matter wave(m/s)
+h=6.6*10**-34;    //plank's constant(Js)
+lamda=600*10**-9;    //wavelength(m)
+//Calculation
+Ej=h*v/lamda;    //matter wave energy(J)
+E=Ej/e;      //matter wave energy(eV)
+//Result
+printf("matter wave energy is %.2e eV",E)
+//answer given in the book is wrong
diff --git a/3768/CH11/EX11.2/Ex11_2.sce b/3768/CH11/EX11.2/Ex11_2.sce
new file mode 100644
index 000000000..59b0ace9c
--- /dev/null
+++ b/3768/CH11/EX11.2/Ex11_2.sce
@@ -0,0 +1,15 @@
+//Example number 11.2, Page number 246
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;     //charge(coulomb)
+c=3*10**10;   //velocity of light(m/s)
+h=6.6*10**-34;    //plank's constant(Js)
+Eg=3;    //energy gap(eV)
+//Calculation
+lamda=h*c*10**9/(Eg*e);     //wavelength of photon(nm)
+//Result
+printf("wavelength of photon is %.f nm",lamda)
+//answer given in the book is wrong
diff --git a/3768/CH11/EX11.3/Ex11_3.sce b/3768/CH11/EX11.3/Ex11_3.sce
new file mode 100644
index 000000000..7db52ccb9
--- /dev/null
+++ b/3768/CH11/EX11.3/Ex11_3.sce
@@ -0,0 +1,15 @@
+//Example number 11.3, Page number 246
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;     //charge(coulomb)
+E2_E1=3*e;    //energy gap(J)
+Kb=1.38*10**-23;    //boltzmann constant(J/K)
+T=323;    //temperature(K)
+//Calculation
+n=exp(-E2_E1/(Kb*T));    //ratio in higher and lower energy
+//Result
+printf("ratio in higher and lower energy is %.4e",n)
+//answer given in the book is wrong
diff --git a/3768/CH11/EX11.4/Ex11_4.sce b/3768/CH11/EX11.4/Ex11_4.sce
new file mode 100644
index 000000000..5879f214c
--- /dev/null
+++ b/3768/CH11/EX11.4/Ex11_4.sce
@@ -0,0 +1,17 @@
+//Example number 11.4, Page number 247
+
+clc;clear;
+close;
+
+//Variable declaration
+c=2.998*10**8;     //velocity of light(m/s)
+Kb=1.381*10**-23;    //boltzmann constant(J/K)
+T=1000;    //temperature(K)
+h=6.626*10**-34;    //plank's constant(Js)
+lamda=0.5*10**-6;   //wavelength(m)
+//Calculation
+v=c/lamda;    //frequency(Hz)
+BA=1/(exp(h*v/(Kb*T))-1);      //ratio of emission
+//Result
+printf("ratio of emission is %.1e",BA)
+//answer varies due to rounding off errors
diff --git a/3768/CH11/EX11.5/Ex11_5.sce b/3768/CH11/EX11.5/Ex11_5.sce
new file mode 100644
index 000000000..5d05afb52
--- /dev/null
+++ b/3768/CH11/EX11.5/Ex11_5.sce
@@ -0,0 +1,14 @@
+//Example number 11.5, Page number 247
+
+clc;clear;
+close;
+
+//Variable declaration
+c=2.998*10**8;     //velocity of light(m/s)
+h=6.626*10**-34;    //plank's constant(Js)
+e=1.602*10**-19;     //charge(coulomb)
+Eg=1.43;    //energy gap(eV)   
+//Calculation
+lamda=h*c*10**6/(Eg*e);        //wavelength(micro m)
+//Result
+printf("wavelength is %.2f micro-m",lamda)
diff --git a/3768/CH12/EX12.1/Ex12_1.sce b/3768/CH12/EX12.1/Ex12_1.sce
new file mode 100644
index 000000000..66a17932d
--- /dev/null
+++ b/3768/CH12/EX12.1/Ex12_1.sce
@@ -0,0 +1,12 @@
+//Example number 12.1, Page number 263
+
+clc;clear;
+close;
+
+//Variable declaration
+NA=0.39;    //numerical aperture
+delta=0.05;     //refractive index of cladding
+//Calculation
+n1=NA/sqrt(2*delta);      //refractive index of core
+//Result
+printf("refractive index of core is %.3f",n1)
diff --git a/3768/CH12/EX12.10/Ex12_10.sce b/3768/CH12/EX12.10/Ex12_10.sce
new file mode 100644
index 000000000..87b1945d7
--- /dev/null
+++ b/3768/CH12/EX12.10/Ex12_10.sce
@@ -0,0 +1,11 @@
+//Example number 12.10, Page number 266
+
+clc;clear;
+close;
+
+//Variable declaration
+theta0=26.80*%pi/180;    //acceptance angle(radian)
+//Calculation
+NA=sin(theta0);       //numerical aperture
+//Result
+printf("numerical aperture is %.5f",NA)
diff --git a/3768/CH12/EX12.2/Ex12_2.sce b/3768/CH12/EX12.2/Ex12_2.sce
new file mode 100644
index 000000000..956111dd4
--- /dev/null
+++ b/3768/CH12/EX12.2/Ex12_2.sce
@@ -0,0 +1,13 @@
+//Example number 12.2, Page number 264
+
+clc;clear;
+close;
+
+//Variable declaration
+n1=1.563;          //Core refractive index
+n2=1.498;          //Cladding refractive index
+//Calculation
+delta=(n1-n2)/n1;    //fractional index change
+//Result
+printf("fractional index change is %.5f",delta)
+
diff --git a/3768/CH12/EX12.3/Ex12_3.sce b/3768/CH12/EX12.3/Ex12_3.sce
new file mode 100644
index 000000000..fce20d664
--- /dev/null
+++ b/3768/CH12/EX12.3/Ex12_3.sce
@@ -0,0 +1,12 @@
+//Example number 12.3, Page number 264
+
+clc;clear;
+close;
+
+//Variable declaration
+n1=1.55;          //Core refractive index
+n2=1.50;          //Cladding refractive index
+//Calculation
+NA=sqrt(n1**2-n2**2);    //numerical aperture
+//Result
+printf("numerical aperture is %.2f",NA)
diff --git a/3768/CH12/EX12.4/Ex12_4.sce b/3768/CH12/EX12.4/Ex12_4.sce
new file mode 100644
index 000000000..b26fb1fbc
--- /dev/null
+++ b/3768/CH12/EX12.4/Ex12_4.sce
@@ -0,0 +1,14 @@
+//Example number 12.4, Page number 264
+
+clc;clear;
+close;
+
+//Variable declaration
+n1=1.563;          //Core refractive index
+n2=1.498;          //Cladding refractive index
+//Calculation
+NA=sqrt(n1**2-n2**2);    //numerical aperture
+theta0=asin(NA);    //acceptance angle(radian)
+theta0=theta0*180/%pi;    //acceptance angle(degrees)
+//Resul"
+printf("acceptance angle is %.2f degree",theta0)
diff --git a/3768/CH12/EX12.5/Ex12_5.sce b/3768/CH12/EX12.5/Ex12_5.sce
new file mode 100644
index 000000000..4035f5170
--- /dev/null
+++ b/3768/CH12/EX12.5/Ex12_5.sce
@@ -0,0 +1,13 @@
+//Example number 12.5, Page number 265
+
+clc;clear;
+close;
+
+//Variable declaration
+n1=1.53;          //Core refractive index
+n2=1.42;          //Cladding refractive index
+//Calculation
+thetac=asin(n2/n1);     //critical angle(radian)
+thetac=thetac*180/%pi;    //critical angle(degrees)
+//Resul"
+printf("critical angle is %.2f degree",thetac)
diff --git a/3768/CH12/EX12.6/Ex12_6.sce b/3768/CH12/EX12.6/Ex12_6.sce
new file mode 100644
index 000000000..06ccff104
--- /dev/null
+++ b/3768/CH12/EX12.6/Ex12_6.sce
@@ -0,0 +1,16 @@
+//Example number 12.6, Page number 265
+
+clc;clear;
+close;
+
+//Variable declaration
+n1=1.6;          //Core refractive index
+n0=1.33;         //refractive index of air
+n2=1.4;          //Cladding refractive index
+//Calculation
+NA=sqrt(n1**2-n2**2)/n0;    //numerical aperture
+theta0=asin(NA);    //acceptance angle(radian)
+theta0=theta0*180/%pi;    //acceptance angle(degrees)
+//Resul"
+printf("acceptance angle is %.2f degree",theta0)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH12/EX12.7/Ex12_7.sce b/3768/CH12/EX12.7/Ex12_7.sce
new file mode 100644
index 000000000..d2c642cf1
--- /dev/null
+++ b/3768/CH12/EX12.7/Ex12_7.sce
@@ -0,0 +1,12 @@
+//Example number 12.7, Page number 265
+
+clc;clear;
+close;
+
+//Variable declaration
+n1=1.5;          //Core refractive index
+n2=1.3;          //Cladding refractive index
+//Calculation
+delta=(n1-n2)/n1;    //fractional index change
+//Result
+printf("fractional index change is %.3f delta",delta)
diff --git a/3768/CH12/EX12.8/Ex12_8.sce b/3768/CH12/EX12.8/Ex12_8.sce
new file mode 100644
index 000000000..cf4f460a5
--- /dev/null
+++ b/3768/CH12/EX12.8/Ex12_8.sce
@@ -0,0 +1,15 @@
+//Example number 12.8, Page number 265
+
+clc;clear;
+close;
+
+//Variable declaration
+n1=1.55;          //Core refractive index
+n2=1.6;          //Cladding refractive index
+theta1=60*%pi/180;     //incident angle(degrees)
+//Calculation
+x=n1*sin(theta1)/n2;
+theta2=asin(x);    //refraction angle(radian)
+theta2=theta2*180/%pi;    //refraction angle(degrees)
+//Result
+printf("refraction angle is %.2f degree",theta2)
diff --git a/3768/CH12/EX12.9/Ex12_9.sce b/3768/CH12/EX12.9/Ex12_9.sce
new file mode 100644
index 000000000..7dbb272b9
--- /dev/null
+++ b/3768/CH12/EX12.9/Ex12_9.sce
@@ -0,0 +1,12 @@
+//Example number 12.9, Page number 266
+
+clc;clear;
+close;
+
+//Variable declaration
+n2=1.3;          //Cladding refractive index
+delta=0.140;    //fractional index change
+//Calculation
+n1=n2/(1-delta);     //Core refractive index
+//Result
+printf("refractive index of core is %.2f",n1)
diff --git a/3768/CH2/EX2.1/Ex2_1.sce b/3768/CH2/EX2.1/Ex2_1.sce
new file mode 100644
index 000000000..8d0fe3f33
--- /dev/null
+++ b/3768/CH2/EX2.1/Ex2_1.sce
@@ -0,0 +1,16 @@
+//Example number 2.1, Page number 31
+
+clc;clear;
+close;
+
+// Variable declaration
+N=6.02*10**26;           // Avagadro Number
+n=8;    // number of atoms
+a=5.6*10**-10;    // lattice constant(m)
+M=72.59;     // atomic weight(amu)
+
+// Calculation
+rho=n*M/(a**3*N);     // density(kg/m**3)
+
+// Result
+printf( "density is %.3f kg/m^3",rho)
diff --git a/3768/CH2/EX2.2/Ex2_2.sce b/3768/CH2/EX2.2/Ex2_2.sce
new file mode 100644
index 000000000..df87f0e2c
--- /dev/null
+++ b/3768/CH2/EX2.2/Ex2_2.sce
@@ -0,0 +1,15 @@
+//Example number 2.2, Page number 32
+
+clc;clear;
+close;
+// Variable declaration
+N=6.02*10**23;           // Avagadro Number
+n=2;
+rho=7860;    // density(kg/m**3)
+M=55.85;    // atomic weight(amu)
+
+// Calculation
+a=(n*M/(rho*N))**(1/3)*10**8;    // lattice constant(angstrom)
+
+// Result
+printf( "lattice constant is %.4f Angstrom",a)
diff --git a/3768/CH2/EX2.3/Ex2_3.sce b/3768/CH2/EX2.3/Ex2_3.sce
new file mode 100644
index 000000000..13169c8bb
--- /dev/null
+++ b/3768/CH2/EX2.3/Ex2_3.sce
@@ -0,0 +1,15 @@
+//Example number 2.3, Page number 32
+clc;clear;
+close;
+
+// Variable declaration
+N=6.02*10**26;           // Avagadro Number
+n=2;
+rho=530;    // density(kg/m**3)
+M=6.94;    // atomic weight(amu)
+
+// Calculation
+a=(n*M/(rho*N))**(1/3)*10**10;    // lattice constant(angstrom)
+
+// Result
+printf( "lattice constant is %.3f Angstrom",a)
diff --git a/3768/CH2/EX2.4/Ex2_4.sce b/3768/CH2/EX2.4/Ex2_4.sce
new file mode 100644
index 000000000..9eb26cebf
--- /dev/null
+++ b/3768/CH2/EX2.4/Ex2_4.sce
@@ -0,0 +1,16 @@
+//Example number 2.4, Page number 32
+
+clc;clear;
+close;
+
+// Variable declaration
+N=6.02*10**26;           // Avagadro Number
+rho=7870;    // density(kg/m**3)
+M=55.85;    // atomic weight(amu)
+a=2.9*10**-10;    // lattice constant(m)
+
+// Calculation
+n=a**3*rho*N/M;      // number of atoms
+
+// Result
+printf( "number of atoms is %d",n)
diff --git a/3768/CH2/EX2.5/Ex2_5.sce b/3768/CH2/EX2.5/Ex2_5.sce
new file mode 100644
index 000000000..96bd510c8
--- /dev/null
+++ b/3768/CH2/EX2.5/Ex2_5.sce
@@ -0,0 +1,17 @@
+//Example number 2.5, Page number 33
+clc;clear;
+close;
+
+// Variable declaration
+N=6.02*10**26;           // Avagadro Number
+M=63.5;    // atomic weight(amu)
+r=0.1278*10**-9;    // atomic radius(m)
+n=4;
+
+// Calculation
+a=r*sqrt(8);    // lattice constant(m)
+rho=n*M/(N*a**3);      // density(kg/m**3)
+
+// Result
+printf( "density is %.2f kg/m**3",rho)
+//answer in the book is wrong
diff --git a/3768/CH2/EX2.6/Ex2_6.sce b/3768/CH2/EX2.6/Ex2_6.sce
new file mode 100644
index 000000000..ef1ee0395
--- /dev/null
+++ b/3768/CH2/EX2.6/Ex2_6.sce
@@ -0,0 +1,19 @@
+//Example number 2.6, Page number 33
+
+clc;clear;
+close;
+
+// Variable declaration
+r1=1.258*10**-10;     // radius(m)
+r2=1.292*10**-10;     // radius(m)
+
+// Calculation
+a_bcc=4*r1/sqrt(3);
+v=a_bcc**3;
+V1=v/2;
+a_fcc=2*sqrt(2)*r2;
+V2=a_fcc**3/4;
+V=(V1-V2)*100/V1;           // percent volume change is",V,"%"
+
+// Result
+printf( "percent volume change is %.1f %%",V)
diff --git a/3768/CH2/EX2.7/Ex2_7.sce b/3768/CH2/EX2.7/Ex2_7.sce
new file mode 100644
index 000000000..1d1415738
--- /dev/null
+++ b/3768/CH2/EX2.7/Ex2_7.sce
@@ -0,0 +1,16 @@
+//Example number 2.7, Page number 34
+
+clc;clear;
+close;
+
+// Variable declaration
+r=poly([0],'r')
+
+// Calculation
+a=4*r/sqrt(2);
+R=(4*r/(2*sqrt(2)))-r
+
+// Result
+printf( "maximum radius of sphere is ")
+disp(R)
+
diff --git a/3768/CH2/EX2.8/Ex2_8.sce b/3768/CH2/EX2.8/Ex2_8.sce
new file mode 100644
index 000000000..1f9885652
--- /dev/null
+++ b/3768/CH2/EX2.8/Ex2_8.sce
@@ -0,0 +1,18 @@
+//Example number 2.8, Page number 34
+clc;clear;
+close;
+
+// Variable declaration
+N=6.023*10**23;           // Avagadro Number
+Mw=23+35.5;        // molecular weight of NaCl
+rho=2.18;    // density(gm/cm**3)
+
+// Calculation
+M=Mw/N;        // mass of 1 molecule(gm)
+Nv=rho/M;      // number of molecules per unit volume(mole/cm**3)
+Na=2*Nv;     // number of atoms
+a=(1/Na)**(1/3)*10**8;   // distance between atoms(angstrom)
+
+// Result
+printf( "distance between atoms is %.2f Angstrom",a)
+
diff --git a/3768/CH3/EX3.1/Ex3_1.sce b/3768/CH3/EX3.1/Ex3_1.sce
new file mode 100644
index 000000000..662f92407
--- /dev/null
+++ b/3768/CH3/EX3.1/Ex3_1.sce
@@ -0,0 +1,15 @@
+//Example number 3.1, Page number 45
+
+clc;clear;
+close;
+
+//Variable declaration
+a=1;
+b=1/2;
+c=3;      //intercepts
+//Calculation
+h=int(c/a);
+k=int(c/b);
+l=int(c/c);     //smiller indices
+//Result
+printf("miller indices are (%d,%d,%d)",h,k,l)
diff --git a/3768/CH3/EX3.10/Ex3_10.sce b/3768/CH3/EX3.10/Ex3_10.sce
new file mode 100644
index 000000000..4b3c2c2ef
--- /dev/null
+++ b/3768/CH3/EX3.10/Ex3_10.sce
@@ -0,0 +1,19 @@
+//Example number 3.10, Page number 49
+clc;clear;
+close;
+
+//Variable declaration
+r=0.1278*10**-9;    //atomic radius(m)
+h1=1;
+k1=1;
+l1=1;
+h2=3;
+k2=2;
+l2=1;
+//Calculation
+a=2*sqrt(2)*r;
+d111=a*10**10/sqrt(h1**2+k1**2+l1**2);    //interplanar spacing for (111)
+d321=a*10**10/sqrt(h2**2+k2**2+l2**2);    //interplanar spacing for (321)
+//Result
+printf("interplanar spacing for (111) is %.3f Angstrom",d111)
+printf("\n interplanar spacing for (321) is %.3f Angstrom",d321)
diff --git a/3768/CH3/EX3.11/Ex3_11.sce b/3768/CH3/EX3.11/Ex3_11.sce
new file mode 100644
index 000000000..09ec5d723
--- /dev/null
+++ b/3768/CH3/EX3.11/Ex3_11.sce
@@ -0,0 +1,17 @@
+//Example number 3.11, Page number 50
+
+clc;clear;
+close;
+
+//Variable declaration
+r1=1.258*10**-10;     //radius(m)
+r2=1.292*10**-10;     //radius(m)
+//Calculation
+a_bcc=4*r1/sqrt(3);
+v=a_bcc**3;
+V1=v/2;
+a_fcc=2*sqrt(2)*r2;
+V2=a_fcc**3/4;
+V=(V1-V2)*100/V1;           //percent volume change is",V,"%"
+//Result
+printf("percent volume change is %.1f %%",V)
diff --git a/3768/CH3/EX3.12/Ex3_12.sce b/3768/CH3/EX3.12/Ex3_12.sce
new file mode 100644
index 000000000..c3d2af8c9
--- /dev/null
+++ b/3768/CH3/EX3.12/Ex3_12.sce
@@ -0,0 +1,17 @@
+//Example number 3.12, Page number 50
+clc;clear;
+close;
+
+//Variable declaration
+C=0.494*10**-9;      //height(m)
+a=0.27*10**-9;      //distance(m)
+M=65.37;      //atomic weight
+N=6.02*10**26;    //avagadro number
+//Calculation
+V=3*sqrt(3)*a**2*C/2;      //volume of cell(m**3)
+m=6*M/N;
+rho=m/V;      //density of Zn(kg/m**3)
+//Result
+printf("volume of cell is %.3e m**3",V)
+printf("\n density of Zn is %.1f kg/m**3",rho)
+//answer in the book is wrong
diff --git a/3768/CH3/EX3.13/Ex3_13.sce b/3768/CH3/EX3.13/Ex3_13.sce
new file mode 100644
index 000000000..61af974f7
--- /dev/null
+++ b/3768/CH3/EX3.13/Ex3_13.sce
@@ -0,0 +1,15 @@
+//Example number 3.13, Page number 51
+
+clc;clear;
+close;
+
+//Variable declaration
+T1=773;    //temperature(K)
+T2=1273;   //temperature(K)
+n=1*10**-10;    //fraction of vacancy sites
+//Calculation
+logx=T1*log(n)/T2
+x=%e**(logx);           //fraction of vacancy sites
+//Result
+printf("fraction of vacancy sites is %.3e",x)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH3/EX3.14/Ex3_14.sce b/3768/CH3/EX3.14/Ex3_14.sce
new file mode 100644
index 000000000..171d2ad39
--- /dev/null
+++ b/3768/CH3/EX3.14/Ex3_14.sce
@@ -0,0 +1,17 @@
+//Example number 3.14, Page number 51
+
+clc;clear;
+close;
+
+//Variable declaration
+Ev=68*10**3;    //enthalpy(j/mol)
+R=8.314;
+T1=300;    //temperature(K)
+T2=800;   //temperature(K)
+//Calculation
+x1=-Ev/(R*T1);
+x2=-Ev/(R*T2);
+n=%e**(x1)/%e**(x2);      //ratio of number of vacancies
+//Result
+printf("ratio of number of vacancies is %.2e",n)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH3/EX3.15/Ex3_15.sce b/3768/CH3/EX3.15/Ex3_15.sce
new file mode 100644
index 000000000..fb2beaf8d
--- /dev/null
+++ b/3768/CH3/EX3.15/Ex3_15.sce
@@ -0,0 +1,16 @@
+//Example number 3.15, Page number 52
+
+clc;clear;
+close;
+
+//Variable declaration
+KbT=0.025;
+nbyN=1/10**10;    //concentration
+N=10**29;
+//Calculation
+x=2*KbT;
+Ev=x*log(1/nbyN);     //value of concentration(eV)
+n=1/((N*nbyN)**(1/3));     //average seperation(m)
+//Result
+printf("value of concentration is %.1f eV",Ev)
+printf("\n average seperation is %.2e m",n)
diff --git a/3768/CH3/EX3.16/Ex3_16.sce b/3768/CH3/EX3.16/Ex3_16.sce
new file mode 100644
index 000000000..6266d7041
--- /dev/null
+++ b/3768/CH3/EX3.16/Ex3_16.sce
@@ -0,0 +1,13 @@
+//Example number 3.16, Page number 52
+
+clc;clear;
+close;
+
+//Variable declaration
+N=2.303*16.65;
+T=298;    //temperature(K)
+Kb=8.625*10**-5;
+//Calculation
+E=2*N*Kb*T;      //energy required(eV)
+//Result
+printf("energy required is %.2f eV",E)
diff --git a/3768/CH3/EX3.5/Ex3_5.sce b/3768/CH3/EX3.5/Ex3_5.sce
new file mode 100644
index 000000000..8fdb4e5ce
--- /dev/null
+++ b/3768/CH3/EX3.5/Ex3_5.sce
@@ -0,0 +1,15 @@
+//Example number 3.5, Page number 48
+
+clc;clear;
+close;
+
+//Variable declaration
+a=1;
+b=2;
+c=3;      //intercepts
+//Calculation
+h=int(c/a);
+k=int(b);
+l=int(c*b);     //miller indices
+//Result
+printf("miller indices are (%d,%d,%d)",h,k,l)
diff --git a/3768/CH3/EX3.7/Ex3_7.sce b/3768/CH3/EX3.7/Ex3_7.sce
new file mode 100644
index 000000000..ee6c81404
--- /dev/null
+++ b/3768/CH3/EX3.7/Ex3_7.sce
@@ -0,0 +1,18 @@
+//Example number 3.7, Page number 48
+
+clc;clear;
+close;
+
+//Variable declaration
+a=poly([0],'a')
+b=poly([0],'b')
+X=3;
+Y=4;
+Z=0;       //intercepts
+//Calculation
+x=a/X;
+y=b/Y;
+z=%inf ;      //miller indices
+//Result
+printf("miller indices are : \n")
+disp (z,y,x)
diff --git a/3768/CH3/EX3.8/Ex3_8.sce b/3768/CH3/EX3.8/Ex3_8.sce
new file mode 100644
index 000000000..90d1a4f9d
--- /dev/null
+++ b/3768/CH3/EX3.8/Ex3_8.sce
@@ -0,0 +1,17 @@
+//Example number 3.8, Page number 49
+
+clc;clear;
+close;
+
+//Variable declaration
+a=0.25;
+b=0.25;
+c=0.18;
+h=1;
+k=1;
+l=1;
+//Calculation
+d_hkl=1/sqrt((a**2/h**2)+(b**2/k**2)+(c**2/l**2));     //spacing between planes(nm)
+//Result
+printf("spacing between planes is %.3f mm",d_hkl)
+//answer in the book is wrong
diff --git a/3768/CH3/EX3.9/Ex3_9.sce b/3768/CH3/EX3.9/Ex3_9.sce
new file mode 100644
index 000000000..3d3408c8c
--- /dev/null
+++ b/3768/CH3/EX3.9/Ex3_9.sce
@@ -0,0 +1,19 @@
+//Example number 3.9, Page number 49
+clc;clear;
+close;
+
+//Variable declaration
+h1=1;
+k1=0;
+l1=0;    //miller indices of (100)
+h2=1;
+k2=1;
+l2=0;    //miller indices of (110)
+a=0.287;    //lattice constant(nm)
+//Calculation
+d100=a/sqrt(h1**2+k1**2+l1**2);    //spacing(nm)
+d110=a/sqrt(h2**2+k2**2+l2**2);    //spacing(nm)
+rho=2/(sqrt(2)*(d100*10**-9)**2);    //number of atoms(per mm**2)
+//Result
+printf("number of atoms is %.3E atoms/mm^2",rho)
+//answer in the book is wrong
diff --git a/3768/CH4/EX4.1/Ex4_1.sce b/3768/CH4/EX4.1/Ex4_1.sce
new file mode 100644
index 000000000..c0ffb5ecc
--- /dev/null
+++ b/3768/CH4/EX4.1/Ex4_1.sce
@@ -0,0 +1,19 @@
+//Example number 4.1, Page number 66
+
+clc;clear;
+close;
+
+//Variable declaration
+d=0.282*10**-9;    //lattice spacing(m)
+theta=8+(35/60);   //glancing angle(degree)
+n=1;   //order
+Theta=90;    //angle(degree)
+//Calculation
+theta=theta*%pi/180;    //angle(radian)
+Theta=Theta*%pi/180;    //angle(radian)
+lamda=2*d*sin(theta)/n;    //wavelength(m)
+nmax=2*d*sin(Theta)/lamda;    //maximum order of diffraction
+//Result
+printf("wavelength is %.3f Angstrom",lamda*10**10)
+//answer varies due to rounding off errors
+printf("\n maximum order of diffraction is %d",round(nmax))
diff --git a/3768/CH4/EX4.10/Ex4_10.sce b/3768/CH4/EX4.10/Ex4_10.sce
new file mode 100644
index 000000000..32e1a87ba
--- /dev/null
+++ b/3768/CH4/EX4.10/Ex4_10.sce
@@ -0,0 +1,21 @@
+//Example number 4.10, Page number 70
+
+clc;clear;
+close;
+
+//Variable declaration
+n=1;   //order
+h=1;
+k=1;
+l=1;
+e=1.6*10**-19;    //charge(c)
+V=5000;    //voltage(V)
+m=9.1*10**-31;    //mass(kg)
+H=6.625*10**-34;   //plank constant
+d=0.204*10**-9;    //interplanar spacing(m)
+//Calculation
+lamda=H/sqrt(2*m*e*V);    //wavelength(m)
+theta=asin(n*lamda/(2*d));    //bragg's angle(radian)
+theta=theta*180/%pi;    //bragg's angle(degree)
+//Result
+printf("bragg''s angle is %.4f degree",theta)
diff --git a/3768/CH4/EX4.2/Ex4_2.sce b/3768/CH4/EX4.2/Ex4_2.sce
new file mode 100644
index 000000000..5350703d7
--- /dev/null
+++ b/3768/CH4/EX4.2/Ex4_2.sce
@@ -0,0 +1,14 @@
+//Example number 4.2, Page number 66
+
+clc;clear;
+close;
+
+//Variable declaration
+d=3.04*10**-10;    //lattice spacing(m)
+n=3;   //order
+lamda=0.79*10**-10;    //wavelength(m)
+//Calculation
+theta=asin(n*lamda/(2*d));     //glancing angle(radian)
+theta=theta*180/%pi;          //glancing angle(degrees)
+//Result
+printf("glancing angle is %.3f degree",theta)
diff --git a/3768/CH4/EX4.3/Ex4_3.sce b/3768/CH4/EX4.3/Ex4_3.sce
new file mode 100644
index 000000000..b69bc2af1
--- /dev/null
+++ b/3768/CH4/EX4.3/Ex4_3.sce
@@ -0,0 +1,19 @@
+//Example number 4.3, Page number 66
+
+clc;clear;
+close;
+
+//Variable declaration
+a=0.28*10**-9;    //lattice spacing(m)
+n=2;   //order
+lamda=0.071*10**-9;    //wavelength(m)
+h=1;
+k=1;
+l=0;
+//Calculation
+d110=a/sqrt(h**2+k**2+l**2);     //spacing(m)
+theta=asin(n*lamda/(2*d110));    //glancing angle(radian)
+theta=theta*180/%pi;          //glancing angle(degrees)
+//Result
+printf("glancing angle is %.2f degree",theta)
+//answer in the book is wrong
diff --git a/3768/CH4/EX4.4/Ex4_4.sce b/3768/CH4/EX4.4/Ex4_4.sce
new file mode 100644
index 000000000..40e9f17c9
--- /dev/null
+++ b/3768/CH4/EX4.4/Ex4_4.sce
@@ -0,0 +1,20 @@
+//Example number 4.4, Page number 67
+
+clc;clear;
+close;
+
+//Variable declaration
+n=1;   //order
+lamda=3*10**-10;    //wavelength(m)
+h=1;
+k=0;
+l=0;
+theta=40;    //angle(degree)
+//Calculation
+theta=theta*%pi/180;    //angle(radian)
+d=n*lamda/(2*sin(theta));     //space of plane(m)
+a=d*sqrt(h**2+k**2+l**2);     
+V=a**3;      //volume of unit cell(m**3)
+//Result
+printf("space of plane is %.4f Angstrom",d*10**10)
+printf("\n volume of unit cell is %.3e m**3",V)
diff --git a/3768/CH4/EX4.5/Ex4_5.sce b/3768/CH4/EX4.5/Ex4_5.sce
new file mode 100644
index 000000000..d8e30486c
--- /dev/null
+++ b/3768/CH4/EX4.5/Ex4_5.sce
@@ -0,0 +1,16 @@
+//Example number 4.5, Page number 67
+
+clc;clear;
+close;
+
+//Variable declaration
+a=3;    //lattice spacing(m)
+n=1;   //order
+lamda=0.82*10**-9;    //wavelength(m)
+theta=75.86;    //angle(degree)
+//Calculation
+theta=theta*%pi/180;    //angle(radian)
+d=n*10**10*lamda/(2*sin(theta));    //spacing(angstrom)
+//Result
+printf("spacing is %.2f Angstrom",d)
+//answer in the book is wrong. hence the miller indices given in the book are also wrong.
diff --git a/3768/CH4/EX4.6/Ex4_6.sce b/3768/CH4/EX4.6/Ex4_6.sce
new file mode 100644
index 000000000..b30ba295f
--- /dev/null
+++ b/3768/CH4/EX4.6/Ex4_6.sce
@@ -0,0 +1,19 @@
+//Example number 4.6, Page number 68
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;    //charge(c)
+m=9.1*10**-31;    //mass(kg)
+h=6.625*10**-34;   //plank constant
+n=1;   //order
+theta=9+(12/60)+(25/(60*60));    //angle(degree)
+V=235.2;    //kinetic energy of electron(eV)
+//Calculation
+theta=theta*%pi/180;    //angle(radian)
+lamda=h*10**10/sqrt(2*m*e*V);   
+d=n*lamda/(2*sin(theta));       //interplanar spacing(angstrom)
+//Result
+printf("interplanar spacing is %.3f Angstrom",d)
+//answer in the book is wrong
diff --git a/3768/CH4/EX4.7/Ex4_7.sce b/3768/CH4/EX4.7/Ex4_7.sce
new file mode 100644
index 000000000..e675bfe57
--- /dev/null
+++ b/3768/CH4/EX4.7/Ex4_7.sce
@@ -0,0 +1,24 @@
+//Example number 4.7, Page number 68
+
+clc;clear;
+close;
+
+//Variable declaration
+n=1;   //order
+h=1;
+k=1;
+l=1;
+e=1.6*10**-19;    //charge(c)
+theta=27.5;    //angle(degree)
+H=6.625*10**-34;    //plancks constant
+c=3*10**10;    //velocity of light(m)
+a=5.63*10**-10;     //lattice constant(m)
+//Calculation
+theta=theta*%pi/180;    //angle(radian)
+d=a/sqrt(h**2+k**2+l**2);
+lamda=2*d*sin(theta)/n;      //wavelength of Xray beam(m)
+E=H*c/(e*lamda);           //energy of Xray beam(eV)         
+//Result
+printf("wavelength of X-ray beam is %.f Angstrom",int32(lamda*10**10))
+printf("\n energy of Xray beam is %.2e eV",E)
+//answer in the book is wrong
diff --git a/3768/CH4/EX4.8/Ex4_8.sce b/3768/CH4/EX4.8/Ex4_8.sce
new file mode 100644
index 000000000..724e9cca8
--- /dev/null
+++ b/3768/CH4/EX4.8/Ex4_8.sce
@@ -0,0 +1,18 @@
+//Example number 4.8, Page number 69
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;    //charge(c)
+theta=56;    //angle(degree)
+V=854;    //voltage(V)
+n=1;      //order of diffraction
+m=9.1*10**-31;    //mass(kg)
+h=6.625*10**-34;   //plank constant
+//Calculation
+theta=theta*%pi/180;    //angle(radian)
+lamda=h/sqrt(2*m*e*V);    //wavelength(m)
+d=n*lamda/(2*sin(theta))*10**10;     //spacing of crystal(Angstrom)
+//Result
+printf("spacing of crystal is %.3f Angstrom",d)
diff --git a/3768/CH4/EX4.9/Ex4_9.sce b/3768/CH4/EX4.9/Ex4_9.sce
new file mode 100644
index 000000000..dd926c384
--- /dev/null
+++ b/3768/CH4/EX4.9/Ex4_9.sce
@@ -0,0 +1,19 @@
+//Example number 4.9, Page number 69
+
+clc;clear;
+close;
+
+//Variable declaration
+n=1;   //order
+h=2;
+k=0;
+l=2;
+theta=34;    //angle(degree)
+lamda=1.5;   //wavelength(angstrom)
+//Calculation
+theta=theta*%pi/180;    //angle(radian)
+d=n*lamda/(2*sin(theta));     //spacing of crystal(angstrom)
+a=d*sqrt(h**2+k**2+l**2);     //lattice parameter(angstrom)
+//Result
+printf("lattice parameter is %.3f Anstrom",a)
+//answer in the book is wrong
diff --git a/3768/CH5/EX5.1/Ex5_1.sce b/3768/CH5/EX5.1/Ex5_1.sce
new file mode 100644
index 000000000..b9b30e1be
--- /dev/null
+++ b/3768/CH5/EX5.1/Ex5_1.sce
@@ -0,0 +1,14 @@
+//Example number 5.1, Page number 85
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;    //charge(c)
+m=9.1*10**-31;    //mass(kg)
+h=6.626*10**-34;   //plank constant
+E=2000;            //energy(eV)
+//Calculation
+lamda=h/sqrt(2*m*E*e)*10**9;    //wavelength(nm)
+//Result
+printf("wavelength is %.4f nm",lamda)
diff --git a/3768/CH5/EX5.10/Ex5_10.sce b/3768/CH5/EX5.10/Ex5_10.sce
new file mode 100644
index 000000000..336480792
--- /dev/null
+++ b/3768/CH5/EX5.10/Ex5_10.sce
@@ -0,0 +1,13 @@
+//Example number 5.10, Page number 88
+
+clc;clear;
+close;
+
+//Variable declaration
+delta_x=10**-8;     //length of box(m)
+m=9.1*10**-31;    //mass(kg)
+h=6.626*10**-34;   //plank constant
+//Calculation
+delta_v=h/(m*delta_x)/10**3;     //uncertainity in velocity(km/s)
+//Result
+printf("uncertainity in velocity is %.1f km/s",delta_v)
diff --git a/3768/CH5/EX5.11/Ex5_11.sce b/3768/CH5/EX5.11/Ex5_11.sce
new file mode 100644
index 000000000..58ca4589f
--- /dev/null
+++ b/3768/CH5/EX5.11/Ex5_11.sce
@@ -0,0 +1,14 @@
+//Example number 5.11, Page number 89
+
+clc;clear;
+close;
+
+//Variable declaration
+me=9.1*10**-31;    //mass(kg)
+mp=1.6*10**-27;    //mass(kg)
+h=6.626*10**-34;   //plank constant
+c=3*10**10;    //velocity of light(m/s)
+//Calculation
+lamda=h/sqrt(2*mp*me*c**2)*10**10;    //de broglie wavelength(m)
+//Result
+printf("de broglie wavelength is %.5e Angstrom",lamda)
diff --git a/3768/CH5/EX5.12/Ex5_12.sce b/3768/CH5/EX5.12/Ex5_12.sce
new file mode 100644
index 000000000..c50f36b6b
--- /dev/null
+++ b/3768/CH5/EX5.12/Ex5_12.sce
@@ -0,0 +1,21 @@
+//Example number 5.12, Page number 89
+
+clc;clear;
+close;
+
+//Variable declaration
+m=1.675*10**-27;    //mass(kg)
+h=6.626*10**-34;   //plank constant
+E=0.04;     //kinetic energy(eV)
+e=1.6*10**-19;    //charge(c)
+n=1;
+d110=0.314*10**-9;   //spacing(m)
+//Calculation
+E=E*e;       //energy(J)
+lamda=h/sqrt(2*m*E);
+theta=asin(n*lamda/(2*d110));     //glancing angle(radian)
+theta=theta*180/%pi;        //glancing angle(degrees)
+theta_m=60*(theta-int(theta));
+//Result
+printf("glancing angle is %d degree and %d minutes",theta,theta_m)
+//answer given in the book is wrong
diff --git a/3768/CH5/EX5.2/Ex5_2.sce b/3768/CH5/EX5.2/Ex5_2.sce
new file mode 100644
index 000000000..5a039acdd
--- /dev/null
+++ b/3768/CH5/EX5.2/Ex5_2.sce
@@ -0,0 +1,12 @@
+//Example number 5.2, Page number 85
+
+clc;clear;
+close;
+
+//Variable declaration
+V=1600;      //potential energy of electron(V)
+//Calculation
+lamda=12.27/sqrt(V);      //wavelength(m)
+//Result
+printf("wavelength is %f Angstrom",lamda)
+//answer given in the book is wrong
diff --git a/3768/CH5/EX5.3/Ex5_3.sce b/3768/CH5/EX5.3/Ex5_3.sce
new file mode 100644
index 000000000..8a4b781ef
--- /dev/null
+++ b/3768/CH5/EX5.3/Ex5_3.sce
@@ -0,0 +1,14 @@
+//Example number 5.3, Page number 85
+
+clc;clear;
+close;
+
+//Variable declaration
+me=9.1*10**-31;    //mass(kg)
+h=6.62*10**-34;   //plank constant
+mn=1.676*10**-27;    //mass(kg)
+c=3*10**8;     //velocity of light(m/s)
+//Calculation
+lamda=h*10**10/sqrt(4*mn*me*c**2);     //de broglie wavelength(angstrom)  
+//Result
+printf("de broglie wavelength is %.1e Angstrom",lamda)
diff --git a/3768/CH5/EX5.4/Ex5_4.sce b/3768/CH5/EX5.4/Ex5_4.sce
new file mode 100644
index 000000000..7ed08dbe9
--- /dev/null
+++ b/3768/CH5/EX5.4/Ex5_4.sce
@@ -0,0 +1,18 @@
+//Example number 5.4, Page number 85
+
+clc;clear;
+close;
+
+//Variable declaration
+a=2*10**-10;    //length(m)
+n1=2;
+n2=4;
+m=9.1*10**-31;    //mass(kg)
+e=1.6*10**-19;    //charge(c)
+h=6.626*10**-34;   //plank constant
+//Calculation
+E2=n1**2*h/(8*m*e*a);      //energy of second state(eV)
+E4=n2**2*h/(8*m*e*a);      //energy of fourth state(eV)
+//Result
+printf("energy of second state is %.5e eV",E2)
+printf("\n energy of second state is %.5e eV",E4)
diff --git a/3768/CH5/EX5.5/Ex5_5.sce b/3768/CH5/EX5.5/Ex5_5.sce
new file mode 100644
index 000000000..7320730a6
--- /dev/null
+++ b/3768/CH5/EX5.5/Ex5_5.sce
@@ -0,0 +1,15 @@
+//Example number 5.5, Page number 86
+
+clc;clear;
+close;
+
+//Variable declaration
+V=344;    //accelerated voltage(V)
+n=1;
+theta=60;   //glancing angle(degrees)
+//Calculation
+theta=theta*%pi/180;    //glancing angle(radian)
+lamda=12.27/sqrt(V);
+d=n*lamda/(2*sin(theta));    //spacing of crystal(angstrom)
+//Result
+printf("spacing of crystal is %.4f Angstrom",d)
diff --git a/3768/CH5/EX5.6/Ex5_6.sce b/3768/CH5/EX5.6/Ex5_6.sce
new file mode 100644
index 000000000..5dd8e9251
--- /dev/null
+++ b/3768/CH5/EX5.6/Ex5_6.sce
@@ -0,0 +1,16 @@
+//Example number 5.6, Page number 86
+
+clc;clear;
+close;
+
+//Variable declaration
+lamda=1.66*10**-10;    //wavelength(m)
+m=9.1*10**-32;    //mass(kg)
+e=1.6*10**-19;    //charge(c)
+h=6.626*10**-34;   //plank constant
+//Calculation
+E=h**2/(4*m*e*lamda**2);   //kinetic energy(eV)
+v=h/(m*lamda);      //velocity(m/s)
+//Result
+printf("kinetic energy is %.2f eV",E)
+printf("\n velocity is %.2e m/s",v)
diff --git a/3768/CH5/EX5.7/Ex5_7.sce b/3768/CH5/EX5.7/Ex5_7.sce
new file mode 100644
index 000000000..c61fc0589
--- /dev/null
+++ b/3768/CH5/EX5.7/Ex5_7.sce
@@ -0,0 +1,21 @@
+//Example number 5.7, Page number 87
+
+clc;clear;
+close;
+
+//Variable declaration
+a=1*10**-10;    //length(m)
+n2=2;
+n3=3;
+m=9.1*10**-31;    //mass(kg)
+e=1.6*10**-19;    //charge(c)
+h=6.626*10**-34;   //plank constant
+//Calculation
+E1=h**2/(8*m*e*a**2);
+E2=n2**2*E1;      //energy of 1st excited state(eV)
+E3=n3**2*E1;      //energy of 2nd excited state(eV)
+//Result
+printf("ground state energy is %.2f eV",E1)
+printf("\n energy of 1st excited state is %.2f eV",E2)
+printf("\n energy of 2nd excited state is %.2f eV",E3)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH5/EX5.8/Ex5_8.sce b/3768/CH5/EX5.8/Ex5_8.sce
new file mode 100644
index 000000000..344382692
--- /dev/null
+++ b/3768/CH5/EX5.8/Ex5_8.sce
@@ -0,0 +1,15 @@
+//Example number 5.8, Page number 88
+
+clc;clear;
+close;
+
+//Variable declaration
+n=poly([0],'n');
+a=4*10**-10;    //width of potential well(m)
+m=9.1*10**-31;    //mass(kg)
+e=1.6*10**-19;    //charge(c)
+h=6.626*10**-34;   //plank constant
+//Calculation
+E1=n**2*h**2/(8*m*e*a**2);     //maximum energy(eV)
+//Result
+disp(E1,"maximum energy in eV is")
diff --git a/3768/CH6/EX6.1/Ex6_1.sce b/3768/CH6/EX6.1/Ex6_1.sce
new file mode 100644
index 000000000..9ac51f358
--- /dev/null
+++ b/3768/CH6/EX6.1/Ex6_1.sce
@@ -0,0 +1,14 @@
+//Example number 6.1, Page number 116
+
+clc;clear;
+close;
+
+//Variable declaration
+rho=1.54*10**-8;    //resistivity(ohm m)
+n=5.8*10**28;       //conduction electrons(per m**3)
+e=1.6*10**-19;      //charge(c)
+m=9.1*10**-31;      //mass(kg)
+//Calculation
+towr=m/(n*e**2*rho);     //relaxation time(sec)
+//Result
+printf("relaxation time is %.4e sec",towr)
diff --git a/3768/CH6/EX6.10/Ex6_10.sce b/3768/CH6/EX6.10/Ex6_10.sce
new file mode 100644
index 000000000..d17578965
--- /dev/null
+++ b/3768/CH6/EX6.10/Ex6_10.sce
@@ -0,0 +1,14 @@
+//Example number 6.10, Page number 120
+
+clc;clear;
+close;
+
+//Variable declaration
+A=10*10**-6;     //area(m**2)
+i=100;    //current(amp)
+n=8.5*10**28;    //number of electrons
+e=1.6*10**-19;      //charge(c)
+//Calculation
+vd=i/(n*A*e);     //drift velocity(m/s)
+//Result
+printf("drift velocity is %.4e m/s",vd)
diff --git a/3768/CH6/EX6.11/Ex6_11.sce b/3768/CH6/EX6.11/Ex6_11.sce
new file mode 100644
index 000000000..9bf638306
--- /dev/null
+++ b/3768/CH6/EX6.11/Ex6_11.sce
@@ -0,0 +1,15 @@
+//Example number 6.11, Page number 121
+
+clc;clear;
+close;
+
+//Variable declaration
+Kb=1.38*10**-23;     //boltzmann constant(J/k)
+m=9.1*10**-31;      //mass(kg)
+tow=3*10**-14;    //relaxation time(sec)
+n=8*10**28;      //density of electrons(per m**3)
+T=273;     //temperature(K)
+//Calculation
+sigma_T=3*n*tow*T*Kb**2/(2*m);      //thermal conductivity(W/mK)
+//Result
+printf("thermal conductivity is %.3f W/mK",sigma_T)
diff --git a/3768/CH6/EX6.2/Ex6_2.sce b/3768/CH6/EX6.2/Ex6_2.sce
new file mode 100644
index 000000000..b7f271d0f
--- /dev/null
+++ b/3768/CH6/EX6.2/Ex6_2.sce
@@ -0,0 +1,17 @@
+//Example number 6.2, Page number 116
+
+clc;clear;
+close;
+
+//Variable declaration
+T=300;    //temperature(K)
+n=8.5*10**28;    //density(per m**3)
+rho=1.69*10**-8;   //resistivity(ohm/m**3)
+e=1.6*10**-19;      //charge(c)
+m=9.11*10**-31;      //mass(kg)
+Kb=1.38*10**-23;     //boltzmann constant(J/k)
+//Calculation
+rho=sqrt(3*Kb*m*T)/(n*e**2*rho);     //mean free path(m)
+//Result
+printf("mean free path is %.2e m",rho)
+//answer given in the book is wrong
diff --git a/3768/CH6/EX6.3/Ex6_3.sce b/3768/CH6/EX6.3/Ex6_3.sce
new file mode 100644
index 000000000..3586942de
--- /dev/null
+++ b/3768/CH6/EX6.3/Ex6_3.sce
@@ -0,0 +1,15 @@
+//Example number 6.3, Page number 117
+
+clc;clear;
+close;
+
+//Variable declaration
+rho=1.43*10**-8;    //resistivity(ohm m)
+n=6.5*10**28;       //conduction electrons(per m**3)
+e=1.6*10**-19;      //charge(c)
+m=9.1*10**-34;      //mass(kg)
+//Calculation
+towr=m/(n*e**2*rho);     //relaxation time(sec)
+//Result
+printf("relaxation time is %.3e sec",towr)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH6/EX6.4/Ex6_4.sce b/3768/CH6/EX6.4/Ex6_4.sce
new file mode 100644
index 000000000..aedbd0795
--- /dev/null
+++ b/3768/CH6/EX6.4/Ex6_4.sce
@@ -0,0 +1,14 @@
+//Example number 6.4, Page number 117
+
+clc;clear;
+close;
+
+//Variable declaration
+PE=1/100;     //probability
+E_EF=0.5;     //energy difference
+//Calculation
+x=log((1/PE)-1);
+T=E_EF/x;     //temperature(K)
+//Result
+printf("temperature is %.4f K",T)
+//answer given in the book is wrong
diff --git a/3768/CH6/EX6.5/Ex6_5.sce b/3768/CH6/EX6.5/Ex6_5.sce
new file mode 100644
index 000000000..db871c62c
--- /dev/null
+++ b/3768/CH6/EX6.5/Ex6_5.sce
@@ -0,0 +1,19 @@
+//Example number 6.5, Page number 117
+
+clc;clear;
+close;
+
+//Variable declaration
+d=8.92*10**3;     //density(kg/m**3)
+rho=1.73*10**-8;    //resistivity(ohm m)
+M=63.5;    //atomic weight
+N=6.02*10**26;    //avagadro number
+e=1.6*10**-19;      //charge(c)
+m=9.1*10**-31;      //mass(kg)
+//Calculation
+n=d*N/M;
+mew=1/(rho*n*e);      //mobility(m/Vs)
+tow=m/(n*e**2*rho);   //average time(sec)
+//Result
+printf("mobility is %.3e m/Vs",mew)
+printf("\n average time is %.2e sec",tow)
diff --git a/3768/CH6/EX6.6/Ex6_6.sce b/3768/CH6/EX6.6/Ex6_6.sce
new file mode 100644
index 000000000..4e395a4e0
--- /dev/null
+++ b/3768/CH6/EX6.6/Ex6_6.sce
@@ -0,0 +1,18 @@
+//Example number 6.6, Page number 118
+
+clc;clear;
+close;
+
+//Variable declaration
+EF=5.5;     //energy(eV)
+FE=10/100;   //probability
+e=1.6*10**-19;      //charge(c)
+Kb=1.38*10**-23;     //boltzmann constant(J/k)
+//Calculation
+E=EF+(EF/100);    
+x=(E-EF)*e;
+y=x/Kb;
+z=(1/FE)-1;
+T=y/log(z);      //temperature(K)
+//Result
+printf("temperature is %.1f K",T)
diff --git a/3768/CH6/EX6.7/Ex6_7.sce b/3768/CH6/EX6.7/Ex6_7.sce
new file mode 100644
index 000000000..d882db653
--- /dev/null
+++ b/3768/CH6/EX6.7/Ex6_7.sce
@@ -0,0 +1,17 @@
+//Example number 6.7, Page number 119
+
+clc;clear;
+close;
+
+//Variable declaration
+Kb=1.38*10**-23;     //boltzmann constant(J/k)
+T=303;     //temperature(K)
+e=1.6*10**-19;      //charge(c)
+MH=2*1.008*1.67*10**-27;   //mass(kg)   
+//Calculation
+KE=3*Kb*T/(2*e);     //kinetic energy(eV)
+cbar=sqrt(3*Kb*T/MH);     //velocity(m/s)
+//Result
+printf("kinetic energy is %.1e eV",KE)
+printf("\n velocity is %.2f m/s",cbar)
+//answer given in the book is wrong
diff --git a/3768/CH6/EX6.8/Ex6_8.sce b/3768/CH6/EX6.8/Ex6_8.sce
new file mode 100644
index 000000000..f23c28e1f
--- /dev/null
+++ b/3768/CH6/EX6.8/Ex6_8.sce
@@ -0,0 +1,20 @@
+//Example number 6.8, Page number 119
+
+clc;clear;
+close;
+
+//Variable declaration
+rho=10**4;      //density of silver(kg/m**3)
+N=6.02*10**26;    //avagadro number
+e=1.6*10**-19;      //charge(c)
+m=9.1*10**-31;      //mass(kg)
+MA=107.9;     //atomic weight(kg)
+sigma=7*10**7;    //conductivity(per ohm m)
+//Calculation
+n=rho*N/MA;       //density of electrons(per m**3)
+mew=sigma/(n*e*10**2);    //mobility of electrons(m**2/Vs)
+tow=sigma*m*10**15/(n*e**2);    //collision time(n sec)
+//Result
+printf("density of electrons is %.1e m^3",n)
+printf("\n mobility of electrons is %.4e m^2/Vs",mew)
+printf("\n collision time is %.1f sec",tow)
diff --git a/3768/CH6/EX6.9/Ex6_9.sce b/3768/CH6/EX6.9/Ex6_9.sce
new file mode 100644
index 000000000..d5c5731b0
--- /dev/null
+++ b/3768/CH6/EX6.9/Ex6_9.sce
@@ -0,0 +1,18 @@
+//Example number 6.9, Page number 120
+
+clc;clear;
+close;
+
+//Variable declaration
+Ee=10;     //electron kinetic energy(eV)
+Ep=10;     //proton kinetic energy(eV)
+e=1.6*10**-19;      //charge(c)
+me=9.1*10**-31;      //mass(kg)
+mp=1.67*10**-27;     //mass(kg)
+//Calculation
+cebar=sqrt(2*Ee*e/me);    //electron velocity(m/s)
+cpbar=sqrt(2*Ep*e/mp);    //proton velocity(m/s)
+//Result
+printf("electron velocity is %.3e m/s",cebar)
+printf("\n proton velocity is %.3e m/s",cpbar)
+//answers given in the book are wrong
diff --git a/3768/CH7/EX7.1/Ex7_1.sce b/3768/CH7/EX7.1/Ex7_1.sce
new file mode 100644
index 000000000..2e3d2e16b
--- /dev/null
+++ b/3768/CH7/EX7.1/Ex7_1.sce
@@ -0,0 +1,19 @@
+//Example number 7.1, Page number 146
+
+clc;clear;
+close;
+
+//Variable declaration
+epsilonr=3.75;       //relative dielectric constant
+T=27;    //temperature(C)
+gama=1/3;     //internal field constant
+rho=2050;     //density(kg/m**3)
+Ma=32;        //atomic weight(amu)
+Na=6.022*10**23;     //avagadro number
+epsilon0=8.85*10**-12;    
+//Calculation
+x=(epsilonr-1)/(epsilonr+2);
+alpha_e=x*Ma*3*epsilon0/(rho*Na);     //electronic polarisability(Fm**2)
+//Result
+printf("electronic polarisability is %.3e Fm^2",alpha_e)
+//answer varies due to rounding off errors
diff --git a/3768/CH7/EX7.10/Ex7_10.sce b/3768/CH7/EX7.10/Ex7_10.sce
new file mode 100644
index 000000000..b217f6ccb
--- /dev/null
+++ b/3768/CH7/EX7.10/Ex7_10.sce
@@ -0,0 +1,15 @@
+//Example number 7.10, Page number 149
+
+clc;clear;
+close;
+
+//Variable declaration
+epsilon0=8.85*10**-12;    
+N=2.7*10**25;   //density of atoms
+R=0.55*10**-10;    //radius(m)
+//Calculation
+alpha_e=4*%pi*epsilon0*R**3;     //polarisability(Fm**2)
+epsilonr=(N*alpha_e/epsilon0)+1;     //relative permittivity
+//Result
+printf("polarisability is %.3e Fm^2",alpha_e)
+printf("\n relative permittivity is %.7f Fm^2",epsilonr)
diff --git a/3768/CH7/EX7.11/Ex7_11.sce b/3768/CH7/EX7.11/Ex7_11.sce
new file mode 100644
index 000000000..0485d0118
--- /dev/null
+++ b/3768/CH7/EX7.11/Ex7_11.sce
@@ -0,0 +1,18 @@
+//Example number 7.11, Page number 150
+
+clc;clear;
+close;
+
+//Variable declaration
+A=180*10**-4;     //area(m**2)
+epsilonr=8;     //relative permittivity
+C=3*10**-6;     //capacitance(F)
+V=10;          //potential(V)
+epsilon0=8.85*10**-12;    
+//Calculation
+E=V*C/(epsilon0*epsilonr);    //field strength(V/m)
+dm=epsilon0*(epsilonr-1)*A*E;     //total dipole moment(coul m)
+//Result
+printf("field strength is %.4e V/m",E)
+printf("\n total dipole moment is %.4e Coul.m",dm)
+//answer in the book is wrong"
diff --git a/3768/CH7/EX7.2/Ex7_2.sce b/3768/CH7/EX7.2/Ex7_2.sce
new file mode 100644
index 000000000..bfd9dbfca
--- /dev/null
+++ b/3768/CH7/EX7.2/Ex7_2.sce
@@ -0,0 +1,16 @@
+//Example number 7.2, Page number 146
+
+clc;clear;
+close;
+
+//Variable declaration
+A=100*10**-4;      //area(m**2)
+epsilon0=8.85*10**-12;    
+d=1*10**-2;     //separation(m)
+V=100;     //potential(V)
+//Calculation
+C=A*epsilon0/d*10**12;     //capacitance(PF)
+Q=(C/10**12)*V;         //charge on plates(C)
+//Result
+printf("capacitance is %.2f pF",C)
+printf("\n charge on plates is %.2e C",Q)
diff --git a/3768/CH7/EX7.3/Ex7_3.sce b/3768/CH7/EX7.3/Ex7_3.sce
new file mode 100644
index 000000000..0ac30db9f
--- /dev/null
+++ b/3768/CH7/EX7.3/Ex7_3.sce
@@ -0,0 +1,14 @@
+//Example number 7.3, Page number 147
+
+clc;clear;
+close;
+
+//Variable declaration
+epsilonr=1.0000684;     //dielectric constant
+N=2.7*10**25;   //number of atoms
+epsilon0=8.85*10**-12;    
+//Calculation
+alpha_e=epsilon0*(epsilonr-1)/N;    //polarisability(Fm**2)
+//Result
+printf("polarisability is %.3e Fm^2",alpha_e)
+//answer varies due to rounding off errors
diff --git a/3768/CH7/EX7.4/Ex7_4.sce b/3768/CH7/EX7.4/Ex7_4.sce
new file mode 100644
index 000000000..1a8cc08c9
--- /dev/null
+++ b/3768/CH7/EX7.4/Ex7_4.sce
@@ -0,0 +1,15 @@
+//Example number 7.4, Page number 147
+
+clc;clear;
+close;
+
+//Variable declaration
+alpha_e=10**-40;      //polarisability(Fm**2)
+N=3*10**28;    //density of atoms
+epsilon0=8.85*10**-12;    
+//Calculation
+x=N*alpha_e/epsilon0;
+epsilonr=(1+(2*x))/(1-x);     //dielectric constant(F/m)
+//Result
+printf("dielectric constant is %.3f F/m",epsilonr)
+//answer in the book is wrong
diff --git a/3768/CH7/EX7.5/Ex7_5.sce b/3768/CH7/EX7.5/Ex7_5.sce
new file mode 100644
index 000000000..dd6f1b5de
--- /dev/null
+++ b/3768/CH7/EX7.5/Ex7_5.sce
@@ -0,0 +1,16 @@
+//Example number 7.5, Page number 147
+
+clc;clear;
+close;
+
+//Variable declaration
+A=650*10**-4;      //area(m**2)
+epsilon0=8.85*10**-12;    
+d=4*10**-2;     //seperation(m)
+Q=2*10**-10;    //charge(C)
+epsilonr=3.5;   //dielectric constant
+//Calculation
+C=A*epsilon0/d;    
+V=Q/C;    //voltage(V)
+//Result
+printf("voltage is %.1f V",V)
diff --git a/3768/CH7/EX7.6/Ex7_6.sce b/3768/CH7/EX7.6/Ex7_6.sce
new file mode 100644
index 000000000..dfcc38273
--- /dev/null
+++ b/3768/CH7/EX7.6/Ex7_6.sce
@@ -0,0 +1,16 @@
+//Example number 7.6, Page number 148
+
+clc;clear;
+close;
+
+//Variable declaration
+A=6.45*10**-4;      //area(m**2)
+epsilon0=8.85*10**-12;    
+d=2*10**-3;     //seperation(m)
+epsilonr=5;   //dielectric constant
+N=6.023*10**23;   //avagadro number
+//Calculation
+alpha_e=epsilon0*(epsilonr-1)/N;    //polarisability(Fm**2)
+//Result
+printf("polarisability is %.3e Fm^2",alpha_e)
+//answer in the book is wrong
diff --git a/3768/CH7/EX7.7/Ex7_7.sce b/3768/CH7/EX7.7/Ex7_7.sce
new file mode 100644
index 000000000..b614da609
--- /dev/null
+++ b/3768/CH7/EX7.7/Ex7_7.sce
@@ -0,0 +1,18 @@
+//Example number 7.7, Page number 148
+
+clc;clear;
+close;
+
+//Variable declaration
+epsilonr=1.0000684;     //dielectric constant
+Na=2.7*10**25;   //number of atoms
+x=1/(9*10**9);   
+E=10**6;   //electric field(V/m)
+e=1.6*10**-19;      //charge(c)
+Z=2;    //atomic number
+//Calculation
+r0=((epsilonr-1)/(4*%pi*Na))**(1/3);     //radius of electron cloud(m)
+X=x*E*r0**3/(Z*e);        //displacement(m)
+//Result
+printf("radius of electron cloud is %.2e m",r0)
+printf("\n displacement is %.4e m",X)
diff --git a/3768/CH7/EX7.8/Ex7_8.sce b/3768/CH7/EX7.8/Ex7_8.sce
new file mode 100644
index 000000000..d4d74e530
--- /dev/null
+++ b/3768/CH7/EX7.8/Ex7_8.sce
@@ -0,0 +1,15 @@
+//Example number 7.8, Page number 149
+
+clc;clear;
+close;
+
+//Variable declaration
+epsilonr=4;       //relative dielectric constant
+Na=2.08*10**23;     //avagadro number
+epsilon0=8.85*10**-12;    
+//Calculation
+x=(epsilonr-1)/(epsilonr+2);
+alpha_e=x*3*epsilon0/Na;     //electronic polarisability(Fm**2)
+//Result
+printf("electronic polarisability is %.3e Fm^2",alpha_e)
+//answer in the book is wrong
diff --git a/3768/CH7/EX7.9/Ex7_9.sce b/3768/CH7/EX7.9/Ex7_9.sce
new file mode 100644
index 000000000..236180aad
--- /dev/null
+++ b/3768/CH7/EX7.9/Ex7_9.sce
@@ -0,0 +1,16 @@
+//Example number 7.9, Page number 149
+
+clc;clear;
+close;
+
+//Variable declaration
+C=4*10**-6;    //capacitance(F)
+epsilonr=200;       //relative dielectric constant
+V=2000;       //voltage(V)
+//Calculation
+C0=C/epsilonr;    //energy in condenser(F)
+E=C0*V/2;      //energy in dielectric(J)
+//Result
+printf("energy in condenser is %.e F",C0)
+printf("\n energy in dielectric is %.1e J",E)
+//answer in the book is wrong 
diff --git a/3768/CH8/EX8.1/Ex8_1.sce b/3768/CH8/EX8.1/Ex8_1.sce
new file mode 100644
index 000000000..ecfd14a52
--- /dev/null
+++ b/3768/CH8/EX8.1/Ex8_1.sce
@@ -0,0 +1,15 @@
+//Example number 8.1, Page number 170
+
+clc;clear;
+close;
+
+//Variable declaration
+r=0.05*10**-9;     //radius(m)
+B=1;     //magnetic induction(web/m**2)
+e=1.6*10**-19;    //charge(c)
+m=9.1*10**-31;    //mass(kg)
+//Calculation
+d_mew=e**2*r**2*B/(4*m);       //change in magnetic moment(Am**2)
+//Result
+printf("change in magnetic moment is %.2e Am^2",d_mew)
+//answer in the book is wrong
diff --git a/3768/CH8/EX8.10/Ex8_10.sce b/3768/CH8/EX8.10/Ex8_10.sce
new file mode 100644
index 000000000..29cde7622
--- /dev/null
+++ b/3768/CH8/EX8.10/Ex8_10.sce
@@ -0,0 +1,15 @@
+//Example number 8.10, Page number 173
+
+clc;clear;
+close;
+
+//Variable declaration
+h=200;     //hysteresis loss per cycle(J/m**3)
+M=7650;    //atomic weight(kg/m**3)
+n=100;     //magnetisation cycles per second
+//Calculation
+hpl=h*n;     //hysteresis power loss per second(watt/m**3)
+pl=hpl/M;    //power loss(watt/kg)
+//Result
+printf("hysteresis power loss per second is %.f W/m^3",hpl)
+printf("\n power loss is %.3f W/kg",pl)
diff --git a/3768/CH8/EX8.2/Ex8_2.sce b/3768/CH8/EX8.2/Ex8_2.sce
new file mode 100644
index 000000000..ee3465952
--- /dev/null
+++ b/3768/CH8/EX8.2/Ex8_2.sce
@@ -0,0 +1,15 @@
+//Example number 8.2, Page number 170
+
+clc;clear;
+close;
+
+//Variable declaration
+chi=-0.5*10**-5;       //magnetic susceptibility
+H=9.9*10**4;        //magnetic field intensity(amp/m)
+mew0=4*%pi*10**-7;
+//Calculation
+I=chi*H;      //intensity of magnetisation(amp/m)
+B=mew0*H*(1+chi);       //magnetic flux density(wb/m**2)
+//Result
+printf("intensity of magnetisation is %.3f amp/m",I)
+printf("\n magnetic flux density is %.3f Wb/m^2",B)
diff --git a/3768/CH8/EX8.3/Ex8_3.sce b/3768/CH8/EX8.3/Ex8_3.sce
new file mode 100644
index 000000000..f5f44ebfd
--- /dev/null
+++ b/3768/CH8/EX8.3/Ex8_3.sce
@@ -0,0 +1,12 @@
+//Example number 8.3, Page number 170
+
+clc;clear;
+close;
+
+//Variable declaration
+H=220;        //magnetic field intensity(amp/m)
+I=3300;      //magnetisation(amp/m)
+//Calculation
+mewr=1+(I/H);      //relative permeability
+//Result
+printf("relative permeability is %d",mewr)
diff --git a/3768/CH8/EX8.4/Ex8_4.sce b/3768/CH8/EX8.4/Ex8_4.sce
new file mode 100644
index 000000000..ac200e1c0
--- /dev/null
+++ b/3768/CH8/EX8.4/Ex8_4.sce
@@ -0,0 +1,18 @@
+//Example number 8.4, Page number 171
+
+clc;clear;
+close;
+
+//Variable declaration
+r=6.1*10**-11;     //radius of atom(m)
+new=8.8*10**15;    //frequency(revolution/sec)
+mew0=4*%pi*10**-7;
+e=1.6*10**-19;    //charge(c)
+//Calculation
+i=e*new;      //current(amp)
+B=mew0*i/(2*r);     //magnetic induction(web/m**2)
+mew=i*%pi*r**2;     //dipole moment(amp m**2)
+//Result
+printf("magnetic induction is %.3f Wb/m^2",B)
+printf("\n dipole moment is %.3e Amp-m^2",mew)
+//answers in the book are wrong
diff --git a/3768/CH8/EX8.5/Ex8_5.sce b/3768/CH8/EX8.5/Ex8_5.sce
new file mode 100644
index 000000000..33337343a
--- /dev/null
+++ b/3768/CH8/EX8.5/Ex8_5.sce
@@ -0,0 +1,15 @@
+//Example number 8.5, Page number 171
+
+clc;clear;
+close;
+
+//Variable declaration
+Is=1.96*10**6;        //saturation magnetisation(amp/m)
+a=3*10**-10;        //cube edge(m)
+mewB=9.27*10**-24;   //bohr magneton(amp/m**2)
+n=2;       //number of atoms
+//Calculation
+N=n/(a**3);      
+mew_bar=Is/(N*mewB);     //average number of bohr magnetons(bohr magneton/atom)
+//Result
+printf("average number of bohr magnetons is %.3f bohr magneton/atom",mew_bar)
diff --git a/3768/CH8/EX8.6/Ex8_6.sce b/3768/CH8/EX8.6/Ex8_6.sce
new file mode 100644
index 000000000..eca43b8ab
--- /dev/null
+++ b/3768/CH8/EX8.6/Ex8_6.sce
@@ -0,0 +1,16 @@
+//Example number 8.6, Page number 172
+
+clc;clear;
+close;
+
+//Variable declaration
+I=3000;      //magnetisation(amp/m)
+mew0=4*%pi*10**-7;
+B=0.005;     //flux density(weber/m**2)
+//Calculation
+H=(B/mew0)-I;      //magnetizing force(amp/m)
+mewr=(I/H)+1;      //relative permeability
+//Result
+printf("magnetizing force is %.3f Amp/m",H)
+printf("\n relative permeability is %.3f",mewr)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH8/EX8.7/Ex8_7.sce b/3768/CH8/EX8.7/Ex8_7.sce
new file mode 100644
index 000000000..ea05d9cb9
--- /dev/null
+++ b/3768/CH8/EX8.7/Ex8_7.sce
@@ -0,0 +1,15 @@
+//Example number 8.7, Page number 172
+
+clc;clear;
+close;
+
+//Variable declaration
+H=1800;      //magnetizing force(amp/m)
+chi=3*10**-5;    //magnetic flux(wb)
+A=0.2*10**-4;    //area(m**2)
+//Calculation
+B=chi/A;
+mew=B/H;     //permeability(henry/m)
+//Result
+printf("permeability is %.3e H/m^2",mew)
+//answer in the book is wrong
diff --git a/3768/CH8/EX8.8/Ex8_8.sce b/3768/CH8/EX8.8/Ex8_8.sce
new file mode 100644
index 000000000..6850d331e
--- /dev/null
+++ b/3768/CH8/EX8.8/Ex8_8.sce
@@ -0,0 +1,20 @@
+//Example number 8.8, Page number 172
+
+clc;clear;
+close;
+
+//Variable declaration
+r=0.04;    //radius(m)
+i=1000*10**-3;    //current(mA)
+B=10**-3;   //magnetic flux density(wb/m**2)
+theta=45;   //angle(degrees)
+//Calculation
+A=%pi*r**2;     //area(m**2)
+mew=i*A;        //magnetic dipole moment(amp m**2)
+theta=theta*%pi/180;
+tow=i*B*cos(theta);    //torque(Nm)
+//Result
+printf("magnetic dipole moment is %.4e Amp-m^2",mew)
+printf("\n torque is %.4e Nm",tow)
+
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH8/EX8.9/Ex8_9.sce b/3768/CH8/EX8.9/Ex8_9.sce
new file mode 100644
index 000000000..50c7d40f8
--- /dev/null
+++ b/3768/CH8/EX8.9/Ex8_9.sce
@@ -0,0 +1,14 @@
+//Example number 8.9, Page number 173
+
+clc;clear;
+close;
+
+//Variable declaration
+A=100;     //area(m**2)
+B=0.01;    //flux density(wb/m**2)
+H=40;      //magnetic field(amp/m)
+M=7650;    //atomic weight(kg/m**3)
+//Calculation
+h=A*B*H;    //hysteresis loss per cycle(J/m**3)
+//Result
+printf("hysteresis loss per cycle is %.f J/m^3",h)
diff --git a/3768/CH9/EX9.1/Ex9_1.sce b/3768/CH9/EX9.1/Ex9_1.sce
new file mode 100644
index 000000000..05d195472
--- /dev/null
+++ b/3768/CH9/EX9.1/Ex9_1.sce
@@ -0,0 +1,14 @@
+//Example number 9.1, Page number 202
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;     //charge(c)
+ni=2.4*10**19;    //particle density(per m**3)
+mew_e=0.39;        //electron mobility(m**2/Vs)
+mew_h=0.19;       //hole mobility(m**2/Vs)
+//Calculation
+rho=1/(ni*e*(mew_e+mew_h));       //resistivity(ohm m)
+//Result
+printf("resistivity is %.5f ohm-m",rho)
diff --git a/3768/CH9/EX9.10/Ex9_10.sce b/3768/CH9/EX9.10/Ex9_10.sce
new file mode 100644
index 000000000..3787b3e1d
--- /dev/null
+++ b/3768/CH9/EX9.10/Ex9_10.sce
@@ -0,0 +1,16 @@
+//Example number 9.10, Page number 207
+
+clc;clear;
+close;
+
+//Variable declaration
+Eg=1.9224*10**-19;    //energy gap of semiconductor(J)
+T1=600;    //temperature(K)
+T2=300;    //temperature(K)
+x=-1.666*10**-3;
+KB=1.38*10**-23;   //boltzmann constant
+//Calculation
+T=(1/T1)-(1/T2);
+r=exp(x*(-Eg/(2*KB)));     //ratio between conductivity
+//Result
+printf("ratio between conductivity is %.3e",r)
diff --git a/3768/CH9/EX9.11/Ex9_11.sce b/3768/CH9/EX9.11/Ex9_11.sce
new file mode 100644
index 000000000..729e4a60a
--- /dev/null
+++ b/3768/CH9/EX9.11/Ex9_11.sce
@@ -0,0 +1,19 @@
+//Example number 9.11, Page number 207
+
+clc;clear;
+close;
+
+//Variable declaration
+ni=2.5*10**19;      //charge carriers(per m**3)
+r=10**-6;    //ratio
+e=1.6*10**-19;     //charge(c)
+mew_e=0.36;        //electron mobility(m**2/Vs)
+mew_h=0.18;       //hole mobility(m**2/Vs)
+N=4.2*10**28;     //number of atoms(per m**3)
+//Calculation
+Ne=r*N;       //number of impurity atoms(per m**3)
+Nh=ni**2/Ne;    
+sigma=(Ne*e*mew_e)+(Nh*e*mew_h);      //conductivity(ohm m)
+rho=1/sigma;     //resistivity of material(per ohm m)
+//Result
+printf("resistivity of material is %.4e ohm-m",rho)
diff --git a/3768/CH9/EX9.12/Ex9_12.sce b/3768/CH9/EX9.12/Ex9_12.sce
new file mode 100644
index 000000000..20ea090b9
--- /dev/null
+++ b/3768/CH9/EX9.12/Ex9_12.sce
@@ -0,0 +1,14 @@
+//Example number 9.12, Page number 208
+
+clc;clear;
+close;
+
+//Variable declaration
+n=5*10**17;     //concentration(m**3)
+vd=350;    //drift velocity(m/s)
+E=1000;    //electric field(V/m)
+e=1.6*10**-19;     //charge(c)
+//Calculation
+sigma=n*e*vd/E;    //conductivity(per ohm m)
+//Result
+printf("conductivity is %.3f per ohm-m",sigma)
diff --git a/3768/CH9/EX9.13/Ex9_13.sce b/3768/CH9/EX9.13/Ex9_13.sce
new file mode 100644
index 000000000..b9e7bc8ae
--- /dev/null
+++ b/3768/CH9/EX9.13/Ex9_13.sce
@@ -0,0 +1,13 @@
+//Example number 9.13, Page number 208
+
+clc;clear;
+close;
+
+//Variable declaration
+sigmae=2.2*10**-4;       //conductivity(ohm/m)
+mew_e=125*10**-3;       //electron mobility(m**2/Vs)
+e=1.602*10**-19;     //charge(c)
+//Calculation
+ne=sigmae/(e*mew_e);     //concentration(per m**3)
+//Result
+printf("concentration is %.1e per m^3",ne)
diff --git a/3768/CH9/EX9.14/Ex9_14.sce b/3768/CH9/EX9.14/Ex9_14.sce
new file mode 100644
index 000000000..550aeaa0e
--- /dev/null
+++ b/3768/CH9/EX9.14/Ex9_14.sce
@@ -0,0 +1,15 @@
+//Example number 9.14, Page number 209
+
+clc;clear;
+close;
+
+//Variable declaration
+RH=3.66*10**-4;      //hall coefficient(m*3/c)
+rho_i=8.93*10**-3;    //resistivity(ohm m)
+e=1.602*10**-19;     //charge(c)
+//Calculation
+nh=1/(RH*e);      //density of charge carriers(per m**3)
+mewh=1/(rho_i*nh*e);     //mobility of charge carriers(m**2/Vs)
+//Result
+printf("density of charge carriers is %.4e per m^3",nh)
+printf("\n mobility of charge carriers is %.3f m^2/Vs",mewh)
diff --git a/3768/CH9/EX9.15/Ex9_15.sce b/3768/CH9/EX9.15/Ex9_15.sce
new file mode 100644
index 000000000..eaa113d5f
--- /dev/null
+++ b/3768/CH9/EX9.15/Ex9_15.sce
@@ -0,0 +1,21 @@
+//Example number 9.15, Page number 209
+
+clc;clear;
+close;
+
+//Variable declaration
+I=3*10**-3;    //current(A)
+RH=3.66*10**-4;    //hall coefficient(m**3/C)
+e=1.6*10**-19;     //charge(c)
+d=2*10**-2;
+z=1*10**-3;
+B=1;        //magnetic field(wb/m**2)
+//Calculation
+w=d*z;     //width(m**2)
+A=w;     //area(m**2)
+EH=RH*I*B/A;    
+VH=EH*d*10**3;     //hall voltage(mV)
+n=1/(RH*e);     //charge carrier concentration(per m**3)
+//Result
+printf("hall voltage is %.1f mH",VH)
+printf("\n charge carrier concentration is %.2e per m^3",n)
diff --git a/3768/CH9/EX9.2/Ex9_2.sce b/3768/CH9/EX9.2/Ex9_2.sce
new file mode 100644
index 000000000..988b2a60d
--- /dev/null
+++ b/3768/CH9/EX9.2/Ex9_2.sce
@@ -0,0 +1,20 @@
+//Example number 9.2, Page number 203
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;     //charge(c)
+ni=1.5*10**16;    //particle density(per m**3)
+mew_e=0.13;        //electron mobility(m**2/Vs)
+mew_h=0.048;       //hole mobility(m**2/Vs)
+ND=10**23;     //density(per m**3)
+//Calculation
+sigma_i=ni*e*(mew_e+mew_h);          //conductivity(s)
+sigma=ND*mew_e*e;       //conductivity(s)
+P=ni**2/ND;            //equilibrium hole concentration(per m**3)
+//Result
+printf("conductivity is %.2e s",sigma_i)
+printf("\n conductivity is %.3e s",sigma)
+printf("\n equilibrium hole concentration is %.2e per m^3",P)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH9/EX9.3/Ex9_3.sce b/3768/CH9/EX9.3/Ex9_3.sce
new file mode 100644
index 000000000..c2d7c7c90
--- /dev/null
+++ b/3768/CH9/EX9.3/Ex9_3.sce
@@ -0,0 +1,19 @@
+//Example number 9.3, Page number 203
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;     //charge(c)
+ni=1.5*10**16;    //particle density(per m**3)
+mew_e=0.13;        //electron mobility(m**2/Vs)
+mew_h=0.05;       //hole mobility(m**2/Vs)
+ND=5*10**20;     //density(per m**3)
+//Calculation
+sigma=ni*e*(mew_e+mew_h);          //intrinsic conductivity(s)
+sigma_d=ND*e*mew_e;       //conductivity during donor impurity(ohm-1 m-1)
+sigma_a=ND*e*mew_h;       //conductivity during acceptor impurity(ohm-1 m-1)
+//Result
+printf("intrinsic conductivity is %.3e (ohm-m)^-1",sigma)
+printf("\n conductivity during donor impurity is %.1f (ohm-m)^-1",sigma_d)
+printf("\n conductivity during donor impurity is %.f (ohm-m)^-1",sigma_a)
diff --git a/3768/CH9/EX9.4/Ex9_4.sce b/3768/CH9/EX9.4/Ex9_4.sce
new file mode 100644
index 000000000..c97979d2f
--- /dev/null
+++ b/3768/CH9/EX9.4/Ex9_4.sce
@@ -0,0 +1,17 @@
+//Example number 9.4, Page number 204
+
+clc;clear;
+close;
+
+//Variable declaration
+RH=3.66*10**-4;     //hall coefficient(m**3/c)
+rho=8.93*10**-3;    //resistivity(m)
+e=1.6*10**-19;     //charge(c)
+//Calculation
+mew=RH/rho;        //mobility(m**2/Vs)
+n=1/(RH*e);      //density of atoms(per m**3)
+//Result
+printf("mobility is %.5f m^2/Vs",mew)
+printf("\n density of atoms is %.1e per m^3",n)
+
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH9/EX9.5/Ex9_5.sce b/3768/CH9/EX9.5/Ex9_5.sce
new file mode 100644
index 000000000..ed97e4289
--- /dev/null
+++ b/3768/CH9/EX9.5/Ex9_5.sce
@@ -0,0 +1,21 @@
+//Example number 9.5, Page number 204
+
+clc;clear;
+close;
+
+//Variable declaration
+w=72.6;       //atomic weight
+e=1.6*10**-19;     //charge(c)
+mew_e=0.4;        //electron mobility(m**2/Vs)
+mew_h=0.2;       //hole mobility(m**2/Vs)
+T=300;         //temperature(K)
+x=4.83*10**21;
+Eg=0.7;      //band gap(eV)
+y=0.052;
+//Calculation
+ni=x*(T**(3/2))*exp(-Eg/y);     //carrier density(per m**3)
+sigma=ni*e*(mew_e+mew_h);         //conductivity(ohm-1 m-1)
+//Result
+printf("carrier density is %.2e per m^3",ni)
+printf("\n conductivity is %.2f (ohm-m)^-1",sigma)
+//answer in the book varies due to rounding off errors
diff --git a/3768/CH9/EX9.6/Ex9_6.sce b/3768/CH9/EX9.6/Ex9_6.sce
new file mode 100644
index 000000000..cec8ed4bf
--- /dev/null
+++ b/3768/CH9/EX9.6/Ex9_6.sce
@@ -0,0 +1,20 @@
+//Example number 9.6, Page number 205
+
+clc;clear;
+close;
+
+//Variable declaration
+T1=293;     //temperature(K)
+T2=305;     //temperature(K)
+e=1.6*10**-19;     //charge(c)
+sigma1=2;    
+sigma2=4.5; 
+KB=1.38*10**-23;   //boltzmann constant
+//Calculation
+x=((1/T1)-(1/T2));
+y=log(sigma2/sigma1);
+z=3*log(T2/T1)/2;
+Eg=2*KB*(y+z)/(e*x);    //energy band gap(eV)
+//Result
+printf("energy band gap is %.2f eV",Eg)
+//answer in the book is wrong
diff --git a/3768/CH9/EX9.7/Ex9_7.sce b/3768/CH9/EX9.7/Ex9_7.sce
new file mode 100644
index 000000000..be5511d10
--- /dev/null
+++ b/3768/CH9/EX9.7/Ex9_7.sce
@@ -0,0 +1,14 @@
+//Example number 9.7, Page number 205
+
+clc;clear;
+close;
+
+//Variable declaration
+e=1.6*10**-19;     //charge(c)
+mew_e=0.19;        //electron mobility(m**2/Vs)
+T=300;         //temperature(K)
+KB=1.38*10**-23;   //boltzmann constant
+//Calculation
+Dn=mew_e*KB*T/e;    //diffusion coefficient(m**2/sec)
+//Result
+printf("diffusion coefficient is %.1e m^2/s",Dn)
diff --git a/3768/CH9/EX9.8/Ex9_8.sce b/3768/CH9/EX9.8/Ex9_8.sce
new file mode 100644
index 000000000..d31a0ee86
--- /dev/null
+++ b/3768/CH9/EX9.8/Ex9_8.sce
@@ -0,0 +1,21 @@
+//Example number 9.8, Page number 206
+
+clc;clear;
+close;
+
+//Variable declaration
+sigma=2.12;     //conductivity(ohm-1 m-1)
+T=300;      //temperature(K)
+e=1.6*10**-19;     //charge(c)
+mew_e=0.36;        //electron mobility(m**2/Vs)
+mew_h=0.7;       //hole mobility(m**2/Vs)
+C=4.83*10**21;
+KB=1.38*10**-23;   //boltzmann constant
+//Calculation
+ni=sigma/(e*(mew_e+mew_h));     //carrier density(per m**3)
+x=C*T**(3/2)/ni;
+Eg=2*KB*T*log(x)/e;      //energy gap(eV)
+//Result
+printf("carrier density is %.2e per m^3",ni)
+printf("\n energy gap is %.2f eV",Eg)
+//answer in the book is wrong
diff --git a/3768/CH9/EX9.9/Ex9_9.sce b/3768/CH9/EX9.9/Ex9_9.sce
new file mode 100644
index 000000000..e6d61e131
--- /dev/null
+++ b/3768/CH9/EX9.9/Ex9_9.sce
@@ -0,0 +1,19 @@
+//Example number 9.9, Page number 206
+
+clc;clear;
+close;
+
+//Variable declaration
+Eg=6.408*10**-20;    //energy gap of semiconductor(J)
+T1=273;    //temperature(K)
+T2=323;    //temperature(K)
+T3=373;    //temperature(K)
+KB=1.38*10**-23;   //boltzmann constant
+//Calculation
+FE1=1/(1+exp(Eg/(2*KB*T1)));     //probability of occupation at 0C(eV)
+FE2=1/(1+exp(Eg/(2*KB*T2)));     //probability of occupation at 50C(eV)
+FE3=1/(1+exp(Eg/(2*KB*T3)));     //probability of occupation at 100C(eV)
+//Result
+printf("probability of occupation at 0C is %.3e eV",FE1)
+printf("\n probability of occupation at 50C is %.2e eV",FE2)
+printf("\n probability of occupation at 100C is %.2e eV",FE3)