7 files changed, 31 insertions, 25 deletions
diff --git a/3411/CH15/EX7.1.u2/Ex7_1_u2.sce b/3411/CH15/EX7.1.u2/Ex7_1_u2.sce
index a17e3227c..016f1977b 100644
--- a/3411/CH15/EX7.1.u2/Ex7_1_u2.sce
+++ b/3411/CH15/EX7.1.u2/Ex7_1_u2.sce
@@ -1,11 +1,13 @@
 //Example 7_1_u2
 clc();
 clear;
-//To calculate the mean free path
-mn=0.26*0.91*10^-30
-un=1000*10^-4
-e=1.6*10^-19
-tc=(mn*un)/e
+//To calculate the mean free path and mean free time
+mn=0.26*0.91*10^-30           //units in Kgs
+un=1000*10^-4        //units in cm^2 V^-1 s^-1
+e=1.6*10^-19          //units in coulombs
+tc=(mn*un)/e         //units in s
+tc1=tc*10^12         //units in ps
+printf("The mean free time is %.3fps",tc1)
 vth=10^7
 meanfreepath=vth*tc*10^7       //units in nm
-printf("The mean free path is given by L=%.1f nm",meanfreepath)
+printf("\nThe mean free path is given by L=%.1f nm",meanfreepath)
diff --git a/3411/CH15/EX7.1.u2/Ex7_1_u2.txt b/3411/CH15/EX7.1.u2/Ex7_1_u2.txt
index f153fb915..b7414acff 100644
--- a/3411/CH15/EX7.1.u2/Ex7_1_u2.txt
+++ b/3411/CH15/EX7.1.u2/Ex7_1_u2.txt
@@ -1 +1,2 @@
+The mean free time is 0.148ps
 The mean free path is given by L=14.8 nm 
 \ No newline at end of file
diff --git a/3411/CH15/EX7.2.u2/Ex7_2_u2.sce b/3411/CH15/EX7.2.u2/Ex7_2_u2.sce
index 2542b76ee..53ba64ccf 100644
--- a/3411/CH15/EX7.2.u2/Ex7_2_u2.sce
+++ b/3411/CH15/EX7.2.u2/Ex7_2_u2.sce
@@ -2,9 +2,9 @@
 clc();
 clear;
 //To calculate the diffusion current density
-Dn=22.5
-e=1.6*10^-19  //units in eV
+Dn=22.5 //units in cm^2/sec
+e=1.6*10^-19  //units in coulombs
 dn=(1*10^18)-(7*10^17)
-dx=0.1
+dx=0.1            //units in cm
 Jndiff=e*Dn*(dn/dx)          //units in A/cm^2
 printf("The diffusion current density is Jn,diff=%.1f A/cm^2",Jndiff)
diff --git a/3411/CH15/EX7.3.u2/Ex7_3_u2.sce b/3411/CH15/EX7.3.u2/Ex7_3_u2.sce
index 13d6b26dd..f6ef6ccc5 100644
--- a/3411/CH15/EX7.3.u2/Ex7_3_u2.sce
+++ b/3411/CH15/EX7.3.u2/Ex7_3_u2.sce
@@ -3,9 +3,9 @@ clc();
 clear;
 //To find the drift velocity and diffusivity
 vp=1/(100*10^-6)           //units in cm/sec
-eapp=50
+eapp=50                   //units in Volt cm^-1
 up=vp/eapp        //units in cm^-2 V^-1 s^-1
-k=0.0259
-dp=(k*up)             //units in cm^2/s
+k=0.0259            //units in eV
+dp=(k*up)             //units in cm^2 s^-1
 printf("The drift velocity is Vp=%d cm/sec\n",vp)
 printf("The diffusivity of minority carriers is Dp=%.2f cm^2/sec",dp)
diff --git a/3411/CH15/EX7.4.u2/Ex7_4_u2.sce b/3411/CH15/EX7.4.u2/Ex7_4_u2.sce
index 474d03e48..388285311 100644
--- a/3411/CH15/EX7.4.u2/Ex7_4_u2.sce
+++ b/3411/CH15/EX7.4.u2/Ex7_4_u2.sce
@@ -2,13 +2,14 @@
 clc();
 clear;
 //To find the charge in the minority carrier concentration
-ni=9.65*10^9
-nno=10^14
+ni=9.65*10^9       //units in cm^-3
+nno=10^14     //units in cm^-3
 //Before illumination
 pno=ni^2/nno      //units in cm^-3
 //After illumination
-tp=2*10^-6
-gl=(10^13/10^-6)
+tp=2          //units in us
+tp=tp*10^-6        //units in sec
+gl=(10^13/10^-6)          //units in No of electron hole pair for cm^-3
 pn=pno+(tp*gl)        //units in cm^-3
 printf("Change in the minority carrier concentration is Pn=")
 disp(pn)
diff --git a/3411/CH15/EX7.5.u2/Ex7_5_u2.sce b/3411/CH15/EX7.5.u2/Ex7_5_u2.sce
index cb96ea6fd..d5629a661 100644
--- a/3411/CH15/EX7.5.u2/Ex7_5_u2.sce
+++ b/3411/CH15/EX7.5.u2/Ex7_5_u2.sce
@@ -2,12 +2,14 @@
 clc();
 clear;
 //To find the hall voltage
-e=1.6*10^-19    //units in eV
-n=10^16
-Rh=-1/(e*n)
-i=10^-3
-Bz=10^-4
-a=2.5*10^-3
-w=500*10^-4
-Vh=((Rh*i*Bz)/a)*w       //units in mV
+e=1.6*10^-19    //units in coulombs
+n=10^16         //units in no of atoms for cm^-3
+Rh=-1/(e*n)         //units in cm^3/C
+i=1            //units in milli amperes
+i=i*10^-3          //units in amperes
+Bz=10^-4      //units in wb/cm^2
+a=2.5*10^-3      //units in cm^2
+w=500*10^-4            //units in micro cm
+Vh=((Rh*i*Bz)/a)*w       //units in V
+Vh=Vh*10^3                //units in mV
 printf("The hall voltage is Vh=%.5f mV",Vh)
diff --git a/3411/CH15/EX7.5.u2/Ex7_5_u2.txt b/3411/CH15/EX7.5.u2/Ex7_5_u2.txt
index 7a73cdce7..3e77f26e6 100644
--- a/3411/CH15/EX7.5.u2/Ex7_5_u2.txt
+++ b/3411/CH15/EX7.5.u2/Ex7_5_u2.txt
@@ -1 +1 @@
-The hall voltage is Vh=-0.00125 mV 
-\ No newline at end of file
+The hall voltage is Vh=-1.25000 mV 
+\ No newline at end of file