initial commit / add all books

40 files changed, 496 insertions, 0 deletions

diff --git a/1511/CH2/EX2.1/ex2_1.sce b/1511/CH2/EX2.1/ex2_1.sce
new file mode 100755
index 000000000..c4bf786b1
--- /dev/null
+++ b/1511/CH2/EX2.1/ex2_1.sce
@@ -0,0 +1,11 @@
+// Example 2.1 page no-45

+clear

+clc

+

+n=1

+h=6.626*10^-34 //J-sec

+eps=10^-9/(36*%pi)

+m=9.1*10^-31 //kg

+e=1.6*10^-19

+r=n^2*h^2*eps/(%pi*m*e^2)

+printf("\nradius of the lowest state of Ground State, r=%.2f A°",r*10^10)

diff --git a/1511/CH2/EX2.10/ex2_10.sce b/1511/CH2/EX2.10/ex2_10.sce
new file mode 100755
index 000000000..487fed008
--- /dev/null
+++ b/1511/CH2/EX2.10/ex2_10.sce
@@ -0,0 +1,16 @@
+// Example 2.10 page no-58

+clear

+clc

+

+//(a)

+h=6.63*10^-34 //Plank's Constant,  J sec.

+e=1.6*10^-19 //Charge of Electron, C

+c=3*10^8 //Velocity of Light, m/sec

+v=0.55     //volts

+l=5500*10^-10 //m

+fi=(h*c)/(l*e)

+fi=fi-v

+printf("\n(a)\nWork Function(WF), fi=%.2f Volts",fi)

+//(b)

+l0=12400/fi

+printf("\n\n(b)\nThreshold Wavelength = %d A°",l0)

diff --git a/1511/CH2/EX2.11/ex2_11.sce b/1511/CH2/EX2.11/ex2_11.sce
new file mode 100755
index 000000000..cc433a71a
--- /dev/null
+++ b/1511/CH2/EX2.11/ex2_11.sce
@@ -0,0 +1,10 @@
+// Example 2.11 page no-59

+clear

+clc

+dT=20

+T=2310 //°K

+Ew=4.52

+k=8.62*10^-5

+x=(Ew/(k*T))

+x=(2+x)*dT/T

+printf("\n(a)\ndIth/Ith=%.1f%%\n\n(b)\nThis is solved by Trial and Error Method to get T = 2370°K",x*100)

diff --git a/1511/CH2/EX2.12/ex2_12.sce b/1511/CH2/EX2.12/ex2_12.sce
new file mode 100755
index 000000000..c8ff7b540
--- /dev/null
+++ b/1511/CH2/EX2.12/ex2_12.sce
@@ -0,0 +1,14 @@
+// Example 2.12 page no-60

+clear

+clc

+

+B=1    //Tesla

+T=35.5*10^-6 //sec

+f=1/T

+printf("\n(a)\nThe frequency of the R.F voltage, f=%.2f*10^4 Hz",f/10^4)

+k=2*10^6

+g=40000

+printf("\n\n(b)Number of passages required to gain 2*10^6 eV are ,N=%d",k/g)

+v=49*g

+R=(3.37*10^-6)*sqrt(v)

+printf("\n\n(c)\nDiameter of last semicircle, D = 2R =%.2f *10^-4 m",2*R*10000)

diff --git a/1511/CH2/EX2.13/ex2_13.sce b/1511/CH2/EX2.13/ex2_13.sce
new file mode 100755
index 000000000..9ec183524
--- /dev/null
+++ b/1511/CH2/EX2.13/ex2_13.sce
@@ -0,0 +1,13 @@
+// Example 2.13 page no-60

+clear

+clc

+Ew=1  //eV

+A0=100 // A/m2 I °K2

+S=1.8*10^-4 //cm2

+K =8.62 * 10^-5  //eV/oK

+T=1100

+pd=5.8*10^4 //W/m^2

+ipd=1.1*pd

+tip=S*ipd

+Ith=S*A0*T^2*%e^(-Ew/(K*T))

+printf("\nIth=%.3f A\nCathode Efficiency, eta=%.0f mA/°K",Ith,ceil(Ith*1000/11.5))

diff --git a/1511/CH2/EX2.14/ex2_14.sce b/1511/CH2/EX2.14/ex2_14.sce
new file mode 100755
index 000000000..b6123190f
--- /dev/null
+++ b/1511/CH2/EX2.14/ex2_14.sce
@@ -0,0 +1,9 @@
+// Example 2.14 page no-71

+clear

+clc

+

+n=4.4*10^22 ///cm^3

+mu=3600//cm62/volt-sec

+e=1.6*10^-19//C

+sigma=n*mu*e*10^-6

+printf("\nResistivity, rho=%.3f Ohm-cm",1/sigma)

diff --git a/1511/CH2/EX2.15/ex2_15.sce b/1511/CH2/EX2.15/ex2_15.sce
new file mode 100755
index 000000000..feae2b0ae
--- /dev/null
+++ b/1511/CH2/EX2.15/ex2_15.sce
@@ -0,0 +1,9 @@
+// Example 2.15 page no-71

+clear

+clc

+mup=500

+mun=1500

+n=1.6*10^10

+e=1.6*10^-19 //c

+sigma=(mun+mup)*e*n

+printf("\nconductivity, sigma=%.2f *10^-6\nResistivity, rho= %d Ohm-cm",sigma*10^6,1/sigma)

diff --git a/1511/CH2/EX2.16/ex2_16.sce b/1511/CH2/EX2.16/ex2_16.sce
new file mode 100755
index 000000000..954ea4124
--- /dev/null
+++ b/1511/CH2/EX2.16/ex2_16.sce
@@ -0,0 +1,12 @@
+// Example 2.16 page no-71

+clear

+clc

+

+A = 9.64 * 10^14

+EG = 0.25 //eV

+n1 = 6.25*10^26///cm^3

+na=3*10^14

+nd=2*10^14

+n=-(10^14)+(sqrt(10^28+4*6.25*10^26))

+n=n/2

+printf("\nn=%.1f*10^12 electrons/cm^3\np=%.2f*10^14 holes/cm^3\nAs p> n, this is p-type semiconductor.",n/10^12,(n+10^14)/10^14)

diff --git a/1511/CH2/EX2.17/ex2_17.sce b/1511/CH2/EX2.17/ex2_17.sce
new file mode 100755
index 000000000..281c6d9e4
--- /dev/null
+++ b/1511/CH2/EX2.17/ex2_17.sce
@@ -0,0 +1,11 @@
+// Example 2.17 page no-72

+clear

+clc

+sigma=100     //Ohm-cm

+e=1.6*10^-19 //c

+mup=1800     //cm^2/V-sec

+ni=2.5*10^13 // /cm^3

+printf("\nIn p-type semiconductor, p>>n.")

+pp=sigma/(e*mup)

+n=ni^2/pp

+printf("\nPp=%.2f*10^17 holes/cm^3\nn=%.1f*10^9 electrons/cm^3",pp/10^17,n/10^9)

diff --git a/1511/CH2/EX2.18/ex2_18.sce b/1511/CH2/EX2.18/ex2_18.sce
new file mode 100755
index 000000000..c156835fe
--- /dev/null
+++ b/1511/CH2/EX2.18/ex2_18.sce
@@ -0,0 +1,21 @@
+// Example 2.18 page no-72

+clear

+clc

+

+//(a)

+sigma=100     //Ohm-cm

+e=1.6*10^-19 //c

+mup=1800     //cm^2/V-sec

+ni=2.5*10^13 // /cm^3

+printf("\n(a)\nAs it is p-type semiconductor, p>>n.")

+pp=sigma/(e*mup)

+n=ni^2/pp

+printf("\nPp=%.2f*10^17 holes/cm^3\nn=%.1f*10^9 electrons/cm^3",pp/10^17,n/10^9)

+

+//(b)

+mun=1300

+sig=0.1

+n1=1.5*10^10

+n2=sig/(mun*e)

+p1=(n1^2)/n2

+printf("\n\n(b)\nn=%.2f*10^14 elecrons/cm^3\np=%.2f*10^5 holes/cm^3",n2/10^14,p1/10^5)

diff --git a/1511/CH2/EX2.19/ex2_19.sce b/1511/CH2/EX2.19/ex2_19.sce
new file mode 100755
index 000000000..c017b87d2
--- /dev/null
+++ b/1511/CH2/EX2.19/ex2_19.sce
@@ -0,0 +1,17 @@
+// Example 2.19 page no-73

+clear

+clc

+sig=1/60 // v/cm

+mup=1800 //cm^2/V-sec

+mun=3800 //cm^2/V-sec

+e=1.6*10^-19 //C

+

+ni=sig/(e*(mun+mup))

+na=7*10^13 //cm^3

+nd=10^14  // /cm^3

+k=na-nd //p-n

+p=0.88*10^13

+n=3.88*10^13

+eps=2

+J=(n*mun+p*mup)*(e*eps)

+printf("J=%.1f mA/cm^3",J*1000)

diff --git a/1511/CH2/EX2.2/ex2_2.sce b/1511/CH2/EX2.2/ex2_2.sce
new file mode 100755
index 000000000..e796394c2
--- /dev/null
+++ b/1511/CH2/EX2.2/ex2_2.sce
@@ -0,0 +1,11 @@
+// Example 2.2 page no-46

+clear

+clc

+

+lambda=2537 //A°

+E_diff=12400/lambda

+e=1.6*10^-19

+energy=50/1000  //J/sec

+e_j=energy/e  //eV/sec

+n=e_j/E_diff

+printf("The lamp emits %.1f *10^16 photons/sec of wavelength, lambda=%dA°",n/10^16,lambda)

diff --git a/1511/CH2/EX2.20/ex2_20.sce b/1511/CH2/EX2.20/ex2_20.sce
new file mode 100755
index 000000000..9bb602176
--- /dev/null
+++ b/1511/CH2/EX2.20/ex2_20.sce
@@ -0,0 +1,10 @@
+// Example 2.20 page no-74

+clear

+clc

+na=3* 10^14 // /cm^3

+nd= 2*10^14 // /cm^3

+ni= 2.5*10^13  // /cm^3

+

+k=na-nd

+n=(-k+sqrt(k^2+4*ni^2))/2

+printf("\nn=%.1f*10^18 electrons/m^3\np=%.2f*10^19 holes/m^3\n\nas p > n, it is p-type semiconductor",n/10^12,ni^2/n*10^-13)

diff --git a/1511/CH2/EX2.21/ex2_21.sce b/1511/CH2/EX2.21/ex2_21.sce
new file mode 100755
index 000000000..13c4d903d
--- /dev/null
+++ b/1511/CH2/EX2.21/ex2_21.sce
@@ -0,0 +1,15 @@
+// Example 2.21 page no-75

+clear

+clc

+

+A=9.64*10^21

+T=320

+e=1.6*10^-19

+Eg=0.75

+k=1.37*10^-23

+ni=A*T^(3/2)*%e^(-(e*Eg)/(2*k*T))

+printf("\nni=%.2f *10^19 electrons(holes)/m^3",ni/10^19)

+mup=0.36

+mun=0.17

+sig=e*ni*(mup+mun)

+printf("\nConductivity, Sigma=%.3f Mho/m",sig)

diff --git a/1511/CH2/EX2.22/ex2_22.sce b/1511/CH2/EX2.22/ex2_22.sce
new file mode 100755
index 000000000..5045488b6
--- /dev/null
+++ b/1511/CH2/EX2.22/ex2_22.sce
@@ -0,0 +1,12 @@
+// Example 2.22 page no-75

+clear

+clc

+

+e=1.6*10^-19//C

+ni=2.5*10^19

+mun=0.36 //m^2/V-sec

+mup=0.17 //m^2/V-sec

+sig=e*ni*(mup+mun)

+

+rho=1/sig

+printf("Resistivity, rho=%.2f Ohm-m",rho)

diff --git a/1511/CH2/EX2.23/ex2_23.sce b/1511/CH2/EX2.23/ex2_23.sce
new file mode 100755
index 000000000..a2322eb45
--- /dev/null
+++ b/1511/CH2/EX2.23/ex2_23.sce
@@ -0,0 +1,8 @@
+// Example 2.23 page no-80

+clear

+clc

+mup=0.4

+T=300

+Nv=4.82*10^15

+Na=Nv*mup^(3/2)*T^(3/2)

+printf("\nDoping concentration, NA=%.2f*10^18 atoms/cm^3",Na/10^18)

diff --git a/1511/CH2/EX2.24/ex2_24.sce b/1511/CH2/EX2.24/ex2_24.sce
new file mode 100755
index 000000000..16b93a204
--- /dev/null
+++ b/1511/CH2/EX2.24/ex2_24.sce
@@ -0,0 +1,6 @@
+// Example 2.24 page no-80

+clear

+clc

+Vt=0.026

+Nv=(3/4)*Vt*log(2)

+printf("\nFor Intrinsic Semiconductor,\nEF will be at the centre of the forbidden band. \nBut if mp and mn are unequal, EF will be away\nfrom the centre of the forbidden band by\n\nNv=%.1f*10^-3 eV",Nv*10^3)

diff --git a/1511/CH2/EX2.25/ex2_25.sce b/1511/CH2/EX2.25/ex2_25.sce
new file mode 100755
index 000000000..3a796c6c1
--- /dev/null
+++ b/1511/CH2/EX2.25/ex2_25.sce
@@ -0,0 +1,13 @@
+// Example 2.25 page no-83

+clear

+clc

+

+si=5*10^22 //atom/cm^3

+d=2*10^8 

+Nd=si/d

+m=9.1*10^-31//kg

+k=1.38*10^-23

+h=6.626*10^-34

+Nc=2*(2*%pi*m*k/h^2)^(3/2)

+T=(Nd/Nc)^(2/3)

+printf("T=%.2f°K",T*10^4)//Nd/10^14)

diff --git a/1511/CH2/EX2.26/ex2_26.sce b/1511/CH2/EX2.26/ex2_26.sce
new file mode 100755
index 000000000..4507c75f2
--- /dev/null
+++ b/1511/CH2/EX2.26/ex2_26.sce
@@ -0,0 +1,17 @@
+// Example 2.25 page no-83

+clear

+clc

+

+m=9.1*10^-31//kg

+k=1.38*10^-23

+h=6.626*10^-34

+T=300

+mp=0.6

+si=5*10^22

+at=10^8

+Nc=si/at

+Nv=2*(2*%pi*m*k*T*mp/h^2)^(3/2)

+printf("\nNv=%.2f * 10^19 /cm^3",Nv/10^25)

+Kt=0.026

+Ediff=Kt*log(1.17*10^19/(5*10^14))

+printf("\nEf-Ev =%.2f eV\nTherefore, EF is above Ev",Ediff)

diff --git a/1511/CH2/EX2.27/ex2_27.sce b/1511/CH2/EX2.27/ex2_27.sce
new file mode 100755
index 000000000..833711358
--- /dev/null
+++ b/1511/CH2/EX2.27/ex2_27.sce
@@ -0,0 +1,8 @@
+// Example 2.27 page no-86

+clear

+clc

+mp=0.4

+T=300

+k=4.82*10^15

+Nv=k*(mp*T)^(3/2)

+printf("Doping concentration, NA = ND = %.2f*10^18 atoms/cm^3",Nv/10^18)

diff --git a/1511/CH2/EX2.28/ex2_28.sce b/1511/CH2/EX2.28/ex2_28.sce
new file mode 100755
index 000000000..04a3dc93f
--- /dev/null
+++ b/1511/CH2/EX2.28/ex2_28.sce
@@ -0,0 +1,6 @@
+// Example 2.28 page no-86

+clear

+clc

+Vt=0.026

+Nv=(3/4)*Vt*log(3)

+printf("\nFor Intrinsic Semiconductor,\nEF will be at the centre of the forbidden band. \nBut if mp and mn are unequal, EF will be away\nfrom the centre of the forbidden band by\n\nNv=%.1f*10^-3 eV",Nv*10^3)

diff --git a/1511/CH2/EX2.29/ex2_29.sce b/1511/CH2/EX2.29/ex2_29.sce
new file mode 100755
index 000000000..d6d263427
--- /dev/null
+++ b/1511/CH2/EX2.29/ex2_29.sce
@@ -0,0 +1,9 @@
+// Example 2.29 page no-90

+clear

+clc

+mung=3800

+mupg=1800

+muns=1300

+mups=500

+Vt=0.026

+printf("\nFor Germanium at room temperature,\nDp=%d cm^2/sec\nDn=%d cm^2/sec\n\nFor Silicon,\nDp=%d cm^2/sec\nDn=%d cm^2/sec",ceil(mupg*Vt),ceil(mung*Vt),ceil(mups*Vt),ceil(muns*Vt))

diff --git a/1511/CH2/EX2.3/ex2_3.sce b/1511/CH2/EX2.3/ex2_3.sce
new file mode 100755
index 000000000..d2f6272be
--- /dev/null
+++ b/1511/CH2/EX2.3/ex2_3.sce
@@ -0,0 +1,10 @@
+// Example 2.3 page no-47

+clear

+clc

+e_ar=11.6 //eV

+e_Na=5.12 //eV

+V=e_ar-e_Na

+e=1.6*10^-19 //C

+m=9.1*10^-31 //kg

+v=sqrt(2*e*V/m)

+printf("Velocity, v=%.2f*10^6 m/sec",v/10^6)

diff --git a/1511/CH2/EX2.30/ex2_30.sce b/1511/CH2/EX2.30/ex2_30.sce
new file mode 100755
index 000000000..83275d945
--- /dev/null
+++ b/1511/CH2/EX2.30/ex2_30.sce
@@ -0,0 +1,13 @@
+// Example 2.30 page no-95

+clear

+clc

+

+B=0.1 //Wb/m^2

+Vh=50 //mV

+I=10 //mA

+rho=2*10^5 //Ohm-cm

+w=3*10^-3 //m

+x=B*I*10^-3/(Vh*10^-2*w)

+printf("\n1/RH=%.3f",x)

+y=1/(rho*10^-2)

+printf("\nConductivity = %f mhos/meter\nmu=%.0f cm^2/V-sec",y,(y/x)*10^6)

diff --git a/1511/CH2/EX2.31/ex2_31.sce b/1511/CH2/EX2.31/ex2_31.sce
new file mode 100755
index 000000000..060b202ce
--- /dev/null
+++ b/1511/CH2/EX2.31/ex2_31.sce
@@ -0,0 +1,16 @@
+// Example 2.31 page no-116

+clear

+clc

+

+//(a)

+Vt=300/11600

+v=Vt*log(1.9)

+printf("\n(a)\nV=%.3fV",v)

+

+//(b)

+v1=0.2

+i1=10*(%e^(v1/Vt)-1)

+printf("\n(b)\nFor V=0.2, I=%.2f mA",i1/1000)

+v2=0.3

+i2=10*(%e^(v2/Vt)-1)

+printf("\n\nFor V=0.3, I=%.2f A",i2/1000000)

diff --git a/1511/CH2/EX2.32/ex2_32.sce b/1511/CH2/EX2.32/ex2_32.sce
new file mode 100755
index 000000000..07fef562e
--- /dev/null
+++ b/1511/CH2/EX2.32/ex2_32.sce
@@ -0,0 +1,13 @@
+// Example 2.32 page no-116

+clear

+clc

+

+Vt=301.6/11600

+i0=20*10^-6

+v=0.1

+I=i0*(%e^(v/Vt)-1)

+printf("\nI=%.3f mA",I*1000)

+r_DC=v/I

+printf("\nr_DC=%.1f Ohm",r_DC)

+r_AC=i0*(%e^(v/Vt))/Vt

+printf("\nr_AC = %.1f Ohm",1/r_AC)

diff --git a/1511/CH2/EX2.33/ex2_33.sce b/1511/CH2/EX2.33/ex2_33.sce
new file mode 100755
index 000000000..5be6a4a58
--- /dev/null
+++ b/1511/CH2/EX2.33/ex2_33.sce
@@ -0,0 +1,19 @@
+// Example 2.33 page no-117

+clear

+clc

+

+A = 0.001// cm2

+sig1n= 1 //mhos/cm,

+sig1p=100 //mhos/cm

+mun=3800 //cm2/sec

+mup = 1800 //cm2/sec.

+e=1.6*10^-19 //C

+eps=16*8.85*10^-14//F/cm

+ni=6.25*10^26

+T=300

+Vt=T/11600

+Nd=sig1n/(e*mun)

+Na=sig1p/(e*mup)

+V0=Vt*log(Na*Nd/ni)

+w=sqrt(2*eps*(V0+1)/(e*Na))

+printf("\nND=%.2f * 10^15 /cm^3\nNA=%.1f * 10^17 /cm^3\nV0=%.3f V\nw=%.3f * 10^-4 cm",Nd*10^-15,Na*10^-17,V0,w*10^4)

diff --git a/1511/CH2/EX2.34/ex2_34.sce b/1511/CH2/EX2.34/ex2_34.sce
new file mode 100755
index 000000000..1623c2637
--- /dev/null
+++ b/1511/CH2/EX2.34/ex2_34.sce
@@ -0,0 +1,18 @@
+// Example 2.34 page no-118

+clear

+clc

+

+I0=10^-6 //A

+T = 301.6  //K

+Vf =0.25 //V

+Vr= 0.25 //V

+//Dynamic Forward Resistance

+Vt=T/11600

+x=(I0*%e^(Vf/Vt))/Vt

+rf=1/x

+printf("\nDynamic Forward Resistance, rf = %.3f Ohm",rf)

+//Dynamic Reverse Resistance

+

+x1=(I0*%e^(-Vf/Vt))/Vt

+rr=1/x1

+printf("\nDynamic Reverse Resistance, rr = %.1f * 10^6 Ohm",rr/10^6)

diff --git a/1511/CH2/EX2.35/ex2_35.sce b/1511/CH2/EX2.35/ex2_35.sce
new file mode 100755
index 000000000..4fbd78316
--- /dev/null
+++ b/1511/CH2/EX2.35/ex2_35.sce
@@ -0,0 +1,11 @@
+// Example 2.35 page no-125

+clear

+clc

+

+eps=16/(36*%pi*10^9) //F/m

+mup=1800

+E=4*10^14

+V=(eps*mup*E*10^-6)/2

+sige=1/45

+Vz=ceil(V)/sige

+printf("V=%d V",Vz)

diff --git a/1511/CH2/EX2.36/ex2_36.sce b/1511/CH2/EX2.36/ex2_36.sce
new file mode 100755
index 000000000..418ce70b6
--- /dev/null
+++ b/1511/CH2/EX2.36/ex2_36.sce
@@ -0,0 +1,9 @@
+// Example 2.36 page no-125

+clear

+clc

+

+Ct=20 //pF

+v1=5 //v

+v2=6 //v

+Ct2=Ct*sqrt(v1/v2)

+printf("Therefore, decrease in the value of capacitance is\nCt1-Ct2=%.2f pF",Ct-Ct2)

diff --git a/1511/CH2/EX2.37/ex2_37.sce b/1511/CH2/EX2.37/ex2_37.sce
new file mode 100755
index 000000000..b6b4caee4
--- /dev/null
+++ b/1511/CH2/EX2.37/ex2_37.sce
@@ -0,0 +1,17 @@
+// Example 2.37 page no-126

+clear

+clc

+V1=200 //V

+Vd=50  //V

+I=40*10^-3 //A

+

+//If Il=0,

+R=(V1-Vd)/I

+I0=5   //mA

+printf("\n(a)\nR=%d Ohm\nImax occurs when I0 = %d mA\nTherefore, Imax = %d mA",R,I0,I*1----I0)

+//for Vmin

+Il=25

+Vmin=Vd+(Il+I0)*0.001*R

+//for Vmax

+Vmax=Vd+(Il+I*1000)*0.001*R

+printf("\n(b)\nFor Vmin\nVmin=%.1fV\n\nFor Vmax\nVmax=%.1fV",Vmin,Vmax)

diff --git a/1511/CH2/EX2.39/ex2_39.sce b/1511/CH2/EX2.39/ex2_39.sce
new file mode 100755
index 000000000..6b91008ee
--- /dev/null
+++ b/1511/CH2/EX2.39/ex2_39.sce
@@ -0,0 +1,13 @@
+// Example 2.39 page no-127

+clear

+clc

+x=99.5 *10^3  //Ohm (R1+R2)

+rm=0.56 *10^3 //Ohm

+v1=20     //V

+i=v1/x

+i=0.0002 //aproxximated to

+k=16/i

+R1=k-rm

+R2=x-R1

+

+printf("\nR1=%.1f K-ohm\nR2=%.1f K-ohm",R1/1000,R2/1000)

diff --git a/1511/CH2/EX2.4/ex2_4.sce b/1511/CH2/EX2.4/ex2_4.sce
new file mode 100755
index 000000000..73a6b6cef
--- /dev/null
+++ b/1511/CH2/EX2.4/ex2_4.sce
@@ -0,0 +1,10 @@
+// Example 2.4 page no-48

+clear

+clc

+

+l=5893 //A°

+V=2.11 //Volts

+e=1.6*10^-19 //C

+m=9.1*10^-31 //kg

+v=sqrt(2*e*V/m)

+printf("Velocity, v=%.2f*10^5 m/sec",v/10^5)

diff --git a/1511/CH2/EX2.40/ex2_40.sce b/1511/CH2/EX2.40/ex2_40.sce
new file mode 100755
index 000000000..21228a842
--- /dev/null
+++ b/1511/CH2/EX2.40/ex2_40.sce
@@ -0,0 +1,10 @@
+// Example 2.40 page no-127

+clear

+clc

+

+T=301.6

+vt=T*1000/11600

+vf=50 //mV

+vr=-50 //mV

+k=(%e^(vf/vt)-1)/(%e^(vr/vt)-1)

+printf("\nratio=%.2f\nNegative sign is oecause, the direction of \ncurrent is opposite when the diode is reverse biased",k)

diff --git a/1511/CH2/EX2.41/ex2_41.sce b/1511/CH2/EX2.41/ex2_41.sce
new file mode 100755
index 000000000..5965f17c2
--- /dev/null
+++ b/1511/CH2/EX2.41/ex2_41.sce
@@ -0,0 +1,11 @@
+// Example 2.41 page no-128

+clear

+clc

+V=10 //v

+I0=0.07/0.11//(0.07/0.11)xI

+i1=5 //mA

+Ir=1-I0

+i=Ir/I0

+Ir=i*i1

+R=V/Ir

+printf("R=%.1f K-Ohm",R)

diff --git a/1511/CH2/EX2.42/ex2_42.sce b/1511/CH2/EX2.42/ex2_42.sce
new file mode 100755
index 000000000..35330439f
--- /dev/null
+++ b/1511/CH2/EX2.42/ex2_42.sce
@@ -0,0 +1,12 @@
+// Example 2.42 page no-128

+clear

+clc

+

+V=30 //V

+R=2000 //Ohm

+I=V/R

+Iz=0.025 //A

+It=Iz+I

+Rs=200

+Vmax=V+Rs*It

+printf("Vrmax = %d V",Vmax)

diff --git a/1511/CH2/EX2.5/ex2_5.sce b/1511/CH2/EX2.5/ex2_5.sce
new file mode 100755
index 000000000..1d3a55552
--- /dev/null
+++ b/1511/CH2/EX2.5/ex2_5.sce
@@ -0,0 +1,19 @@
+// Example 2.5 page no-48

+clear

+clc

+

+f=10*10^6 //Hz

+h=6.626*10^-34 //Joules/sec

+e=1.6*10^-19 //C

+//(a)

+E=h*f/e

+printf("\n(a)Energy of each radiated quantum,\n\tE=%.3f*10^-27 Joules/Quantum\n\tE=%.2f*10^-8 eV/Quantum",h*f*10^27,E*10^8)

+

+//(b)

+E=1000  //Joule/sec

+N=E/(h*f)

+printf("\n\n(b)\nTotal number of quanta per sec, N=%.2f*10^29",N/10^29)

+

+//(c)

+o=10^-7

+printf("\n\n(c)\nNumber of quanta emitted per cycle = %.2f*10^22 per cycle",o*N/10^22)

diff --git a/1511/CH2/EX2.6/ex2_6.sce b/1511/CH2/EX2.6/ex2_6.sce
new file mode 100755
index 000000000..aadf28a31
--- /dev/null
+++ b/1511/CH2/EX2.6/ex2_6.sce
@@ -0,0 +1,15 @@
+// Example 2.6 page no-48

+clear

+clc

+

+//(a)

+V=21.5 //Volts

+e=1.6*10^-19 //C

+m=9.1*10^-31 //kg

+v=sqrt(2*e*V/m)

+lambda=12400/V //A°

+printf("\n(a)\nVelocity, v=%.2f*10^6 m/sec\nWavelength of Radiation, Lambda=%.1f",v/10^6,ceil(lambda))

+//(b)

+c=3*10^8 //m/sec

+f=c/(lambda*10^-10)

+printf("\n(b)\nFrequency of Radiation, f=%.1f*10^15 Hz",f/10^15)

diff --git a/1511/CH2/EX2.8/ex2_8.sce b/1511/CH2/EX2.8/ex2_8.sce
new file mode 100755
index 000000000..94f3510c8
--- /dev/null
+++ b/1511/CH2/EX2.8/ex2_8.sce
@@ -0,0 +1,8 @@
+// Example 2.8 page no-49

+clear

+clc

+L=1400

+E_diff=12400/L //eV

+del_E=2.15

+L2=12400/del_E

+printf("\nE2-E1=%.2f eV\n1850 A° line is from 6.71 eV to 0 eV\nTherefore, second photon must be from %.2f to 6.71 eV.\nLambda=%d A°.",E_diff,E_diff,L2)

diff --git a/1511/CH2/EX2.9/ex2_9.sce b/1511/CH2/EX2.9/ex2_9.sce
new file mode 100755
index 000000000..f4fbceec2
--- /dev/null
+++ b/1511/CH2/EX2.9/ex2_9.sce
@@ -0,0 +1,14 @@
+// Example 2.9 page no-58

+clear

+clc

+A=60.2*10^4 //A/m^2/°K^2

+B=52400    //°K

+T1=2400    //°K

+T2=2410    //°K

+js1=A*T1^2*(%e^(-B/T1))

+js2=A*T2^2*(%e^(-B/T2))

+js1=floor(js1)

+js2=floor(js2)

+printf("\nJS1=%d A/m^2\nJS2=%d A/m^2",js1,js2)

+p=(js2-js1)*100/js1

+printf("\nPercentage Increase=%.2f%%",p)