1 files changed, 22 insertions, 0 deletions
diff --git a/2912/CH6/EX6.4/Ex6_4.sce b/2912/CH6/EX6.4/Ex6_4.sce
new file mode 100755
index 000000000..daf83e29c
--- /dev/null
+++ b/2912/CH6/EX6.4/Ex6_4.sce
@@ -0,0 +1,22 @@
+//chapter 6
+//example 6.4
+//Calculate mean free path traveeled by the electrons
+//page 147
+clear;
+clc;
+//given
+n=8.5E28; // in 1/m^3 (density of electron)
+m=9.1E-31; // in Kg (mass of electron)
+e=1.6E-19; // in C (charge of electron)
+sigma=6E7; // in 1/ohm-m (conductivity)
+E_F=7; // in E=eV (Fermi energy of Copper)
+//calculate
+E_F=E_F*e; // changing unit from eV to J
+v_F=sqrt(2*E_F/m); // calculation of velocity of electrons
+printf('\nThe velocity of the electrons is \t\t\tv_F=%1.1E m/s',v_F);
+// Since sigma=n*e^2*lambda/(2*m*v_F)
+// Therefore we have
+lambda=2*m*v_F*sigma/(n*e^2); // calculation of mean free path
+lambda=lambda*1E10; // changing unit from m to Angstrom
+printf('\n\nThe mean free path traveled by the electrons is \t%.f Angstrom',lambda);
+// Note: Answer in the book is wrong due to the use of round-off value of v_F as calculated in the first part.