7 files changed, 119 insertions, 0 deletions
diff --git a/3828/CH12/EX12.1/Ex12_1.sce b/3828/CH12/EX12.1/Ex12_1.sce
new file mode 100644
index 000000000..e6c410bcb
--- /dev/null
+++ b/3828/CH12/EX12.1/Ex12_1.sce
@@ -0,0 +1,17 @@
+//Chapter 12 : Semiconductor Physics
+
+clear;
+
+//Variable declaration
+ni=2.5*10**19          //intrinsic concentration 
+myun=0.40              //mobility of electrons 
+myup=0.25              //mobility of holes
+e=1.6*10**-19
+
+//Calculations
+sigmai=ni*e*(myun+myup) //conductivity of intrinsic semiconductor
+rhoi=1/sigmai
+
+//Result
+mprintf("Resistivity = %f ohm-m",rhoi)
+
diff --git a/3828/CH12/EX12.2/Ex12_2.sce b/3828/CH12/EX12.2/Ex12_2.sce
new file mode 100644
index 000000000..caa2620c9
--- /dev/null
+++ b/3828/CH12/EX12.2/Ex12_2.sce
@@ -0,0 +1,16 @@
+//Chapter 12 : Semiconductor Physics
+
+clear;
+
+//Variable declaration
+myun=0.36              //mobility of electrons 
+myup=0.14              //mobility of holes
+e=1.6*10**-19  
+rhoi=2.2               //resistivity
+
+//Calculations
+ni=1/(rhoi*e*(myun+myup))/10**18
+
+//Result
+mprintf("Intrinsic concentration= %.3f*10**18 m**-3",ni)
+
diff --git a/3828/CH12/EX12.3/Ex12_3.sce b/3828/CH12/EX12.3/Ex12_3.sce
new file mode 100644
index 000000000..712712f20
--- /dev/null
+++ b/3828/CH12/EX12.3/Ex12_3.sce
@@ -0,0 +1,19 @@
+//Chapter 12 : Semiconductor Physics
+
+clear;
+
+//Variable declaration
+myun=0.39              //mobility of electrons 
+myup=0.21              //mobility of holes
+ni=2.5*10**19          //intrinsic concentration 
+e=1.6*10**-19  
+
+//Calculations
+sigmai=ni*e*(myun+myup) //conductivity of intrinsic semiconductor
+rhoi=1/sigmai
+
+//Result
+mprintf("Conductivity = %.1f ohm**-1-m**-1",sigmai)
+mprintf("\nResistivity= %.2f ohm-m",rhoi)
+//The answer provided in the textbook is wrong
+
diff --git a/3828/CH12/EX12.4/Ex12_4.sce b/3828/CH12/EX12.4/Ex12_4.sce
new file mode 100644
index 000000000..50d39dc4f
--- /dev/null
+++ b/3828/CH12/EX12.4/Ex12_4.sce
@@ -0,0 +1,18 @@
+//Chapter 12 : Semiconductor Physics
+
+clear;
+
+//Variable declaration
+Eg=0.8                 //Energy gap width
+T=300
+m=9.1*10**-31          //mass of electron
+k=1.38*10**-23
+h=6.63*10**-34         
+
+//Calculations
+ni=2*((2*22*m*k*T)/(7*h**2))**(3/2)*exp((-Eg*1.6*10**-19)/(2*k*T))/10**18
+
+//Result
+mprintf("Concentration of intrinsic charge= %.2f*10**18 /m**3",ni)
+ //The answer provided in the textbook is wrong
+
diff --git a/3828/CH12/EX12.5/Ex12_5.sce b/3828/CH12/EX12.5/Ex12_5.sce
new file mode 100644
index 000000000..650e4244d
--- /dev/null
+++ b/3828/CH12/EX12.5/Ex12_5.sce
@@ -0,0 +1,17 @@
+//Chapter 12 : Semiconductor Physics
+
+clear;
+
+//Variable declaration
+RH=3.22*10**-4         //Hall coefficient
+rho=9.0*10**-3
+e=1.6*10**-19
+
+//Calculations
+p=1/(RH*e)/10**21
+myup=RH/rho
+
+//Result
+mprintf("Hole concentration= %.2f*10**21 m**-3",p)
+mprintf("\nMobility of holes= %.5f m**2 V**-1 s**-1",myup)
+
diff --git a/3828/CH12/EX12.6/Ex12_6.sce b/3828/CH12/EX12.6/Ex12_6.sce
new file mode 100644
index 000000000..efd2cdb1f
--- /dev/null
+++ b/3828/CH12/EX12.6/Ex12_6.sce
@@ -0,0 +1,16 @@
+//Chapter 12 : Semiconductor Physics
+
+clear;
+
+//Variable declaration
+RH=3.66*10**-4         //Hall coefficient
+t=10**-3               //thickness
+I=1                    //current
+B=0.5                  //magnetic induction
+
+//Calculations
+VH=(RH*I*B)/t
+
+//Result
+mprintf("Hall voltage VH= %.3f V",VH)
+
diff --git a/3828/CH12/EX12.7/Ex12_7.sce b/3828/CH12/EX12.7/Ex12_7.sce
new file mode 100644
index 000000000..d9a79c2e6
--- /dev/null
+++ b/3828/CH12/EX12.7/Ex12_7.sce
@@ -0,0 +1,16 @@
+//Chapter 12 : Semiconductor Physics
+
+clear;
+
+//Variable declaration
+RH=7.5*10**-5         //Hall coefficient
+sigma=200              //conductivity
+e=1.6*10**-19          //electron charge
+
+//Calculations
+n=1/(e*RH)/10**22
+myu=sigma*RH
+
+//Result
+mprintf("Charge density= %.2f*10**22 /m**3",n)
+mprintf("\nMobility= %.3f m**2 V**-1 s**-1",myu)