initial commit / add all books

8 files changed, 89 insertions, 0 deletions

diff --git a/2453/CH4/EX4.1/4_1.sce b/2453/CH4/EX4.1/4_1.sce
new file mode 100755
index 000000000..a25126f1e
--- /dev/null
+++ b/2453/CH4/EX4.1/4_1.sce
@@ -0,0 +1,12 @@
+//To calculate the density and mobility of electrons

+rho_s = 10.5*10^3;    //density of silver, kg/m^3

+NA = 6.02*10^26;     //avagadro number, /k-mol

+MA = 107.9;     //atomic weight of silver

+n = rho_s*NA/MA;      //molar volume of silver

+printf("density of electrons in silver is");

+disp(n);

+sigma = 6.8*10^7;     //conductivity of silver, ohm-1 m-1

+e = 1.6*10^-19;

+mew = sigma/(n*e);     //mobility of electrons, m^2/Vs

+printf("mobility of electrons is %5.5f m^2/Vs",mew);

+

diff --git a/2453/CH4/EX4.2/4_2.sce b/2453/CH4/EX4.2/4_2.sce
new file mode 100755
index 000000000..53f0b8f82
--- /dev/null
+++ b/2453/CH4/EX4.2/4_2.sce
@@ -0,0 +1,13 @@
+//To calculate the mobility of electrons

+d = 8.92*10^3;      //density, kg/m^3

+e = 1.6*10^-19;

+m = 9.1*10^-31;      //mass of electron, kg

+N = 6.02*10^26;      //avagadro's number per k-mol

+AW = 63.5;     //atomic weight

+rho = 1.73*10^-8;     //resistivity of copper, ohm-m

+n = d*N/AW;       //number of cu atoms/m^3

+mew = 1/(rho*n*e);      //mobility of electrons, m/Vs

+printf("mobility of electrons is %f m/Vs",mew);

+tow = m/(n*e^2*rho);    //relaxation time, s

+printf("relaxation time in sec is");

+disp(tow);

diff --git a/2453/CH4/EX4.3/4_3.sce b/2453/CH4/EX4.3/4_3.sce
new file mode 100755
index 000000000..13ab355b8
--- /dev/null
+++ b/2453/CH4/EX4.3/4_3.sce
@@ -0,0 +1,8 @@
+//To calculate the relaxation time

+rho = 1.54*10^-8;      //resistivity, ohm-m

+n = 5.8*10^28;      //conduction electrons per m^3

+m = 9.108*10^-31;    //mass of electron, kg

+e = 1.602*10^-19;

+tow = m/(n*e^2*rho);    //relaxation time, sec

+printf("relaxation time of conduction electrons in sec is");

+disp(tow);

diff --git a/2453/CH4/EX4.4/4_4.sce b/2453/CH4/EX4.4/4_4.sce
new file mode 100755
index 000000000..c0140d62d
--- /dev/null
+++ b/2453/CH4/EX4.4/4_4.sce
@@ -0,0 +1,17 @@
+//To calculate the free electron concentration, mobility and drift velocity

+R = 0.06;      //resistance, ohm

+D = 5;      //length of Al wire, m

+e = 1.602*10^-19;

+rho = 2.7*10^-8;     //resistivity of Al, ohm-m

+MA = 26.98;     //atomic weight

+NA = 6.025*10^26;     //avagadro number, k/mol

+rho_s = 2.7*10^3;     //density, kg/m^3

+n = 3*rho_s*NA/MA;     //free electron concentration, electrons/m^3

+printf("free electron concentration in electrons/m^3 is");

+disp(n);

+mew = 1/(n*e*rho);     //mobility, m/Vs

+printf("mobility is %f m/Vs",mew);

+I = 15;     //current, A

+E = I*R/D;      //electric field, V/m

+vd = mew*E;     //drift velocity, m/s

+printf("drift velocity is %f m/s",vd);

diff --git a/2453/CH4/EX4.5/4_5.sce b/2453/CH4/EX4.5/4_5.sce
new file mode 100755
index 000000000..e1a6e6898
--- /dev/null
+++ b/2453/CH4/EX4.5/4_5.sce
@@ -0,0 +1,12 @@
+//To calculate the lowest energy of an electron

+n1 = 1;

+n2 = 1;

+n3 = 1;      //for lowest energy

+h = 6.62*10^-34;     //planck's constant, Js

+e = 1.6*10^-19;

+m = 9.1*10^-31;      //mass of electron, kg

+L = 0.1;     //side of box, nm

+L = L*10^-9;    //side of box, m

+E1 = h^2*(n1^2+n2^2+n3^2)/(8*m*L^2);      //lowest energy, J

+E1 = E1/e;        //lowest energy, eV

+printf("lowest energy of electron is %5.1f eV",E1);

diff --git a/2453/CH4/EX4.6/4_6.sce b/2453/CH4/EX4.6/4_6.sce
new file mode 100755
index 000000000..0510aabd9
--- /dev/null
+++ b/2453/CH4/EX4.6/4_6.sce
@@ -0,0 +1,5 @@
+//To evaluate the fermi function

+//Fermi function F(E) = 1/(1+exp((E-Ef)/(kT)))

+//given E-Ef = kT. therefore F(E) = 1/(1+exp(1))

+F_E = 1/(1+exp(1));

+printf("fermi function is %5.3f",F_E);

diff --git a/2453/CH4/EX4.7/4_7.sce b/2453/CH4/EX4.7/4_7.sce
new file mode 100755
index 000000000..a3fe0b446
--- /dev/null
+++ b/2453/CH4/EX4.7/4_7.sce
@@ -0,0 +1,11 @@
+

+//To calculate the temperature

+F_E = 10;      //probability in percent

+k = 1.38*10^-23;

+e = 1.6*10^-19;    //conversion factor

+EF = 5.5;      //fermi energy, eV

+E = EF+(EF/100);     //energy, eV

+X = E-EF;     //E-EF, eV

+X = X*e;      //E-EF, J

+T = X/(k*log(F_E-1));      //temperature, K

+printf("temperature is %5.1f K",T);

diff --git a/2453/CH4/EX4.8/4_8.sce b/2453/CH4/EX4.8/4_8.sce
new file mode 100755
index 000000000..695b73824
--- /dev/null
+++ b/2453/CH4/EX4.8/4_8.sce
@@ -0,0 +1,11 @@
+//To calculate the temperature

+F_E = 0.01;      //probability in percent

+k = 1.38*10^-23;

+e = 1.6*10^-19;

+//let E-EF be X

+X = 0.5;      //E-EF, eV

+kT = X/(2.303*log10((1-F_E)*100));    //value of kT, eV

+T = kT*e/k;        //temperature, K

+printf("temperature is %d K",T);

+

+//answer given in the book is wrong