initial commit / add all books

25 files changed, 510 insertions, 0 deletions

diff --git a/2444/CH4/EX4.1/ex4_1.sce b/2444/CH4/EX4.1/ex4_1.sce
new file mode 100755
index 000000000..dd82b5bdc
--- /dev/null
+++ b/2444/CH4/EX4.1/ex4_1.sce
@@ -0,0 +1,39 @@
+// Exa 4.1

+clc;

+clear;

+close;

+format('v',8)

+// Given data

+V_CC = 20;// in V

+I_C= 2*10^-3;// in A

+I_CQ= I_C;// in A

+I_E=I_C;// in A

+R_C = 3;// in k ohm

+R_C = R_C * 10^3;// in ohm

+R_L = 12;// in k ohm

+R_L = R_L * 10^3;// in ohm

+R_E = 2;// in k ohm 

+R_E = R_E * 10^3;// in ohm

+V_CE=0:0.1:20;// in V

+I_C_sat= (V_CC-V_CE)/(R_C+R_E)*10^3;// in mA

+subplot(121)

+plot(V_CE,I_C_sat);

+xlabel("V_CE in volts")

+ylabel("I_C in mA")

+title("DC load line")

+Rac= R_C*R_L/(R_C+R_L);// in ohm

+V_CEQ= V_CC-I_CQ*(R_C+R_E);// in V

+I_Csat= I_CQ+V_CEQ/Rac;// in A

+I_Csat=I_Csat*10^3;// in mA

+V_CEoff= V_CEQ+I_CQ*Rac;// in V

+subplot(122)

+plot([V_CEoff 0],[0,I_Csat])

+xlabel("V_CE in volts")

+ylabel("I_C in mA")

+title("AC load line")

+// Maximum peak output signal

+POSmax= I_CQ*Rac;// in V

+// Peak-to-peak value of output signal

+PP_out_sig= 2*POSmax;// in V

+disp(PP_out_sig,"Peak-to-peak value of output signal in volts is : ")

+disp("DC and AC load line shown in figure.")

diff --git a/2444/CH4/EX4.10/ex4_10.sce b/2444/CH4/EX4.10/ex4_10.sce
new file mode 100755
index 000000000..caf44992a
--- /dev/null
+++ b/2444/CH4/EX4.10/ex4_10.sce
@@ -0,0 +1,14 @@
+// Exa 4.10

+clc;

+clear;

+close;

+format('v',8)

+// Given data

+V1 = 10;// in V

+V2 = 5;// in V

+I1 = 5.8;// in mA

+I2 = 5;// in mA

+delV_C = V1-V2;// in V

+delI_C = I1-I2;// in mA

+r_out = delV_C/delI_C;// in k ohm

+disp(r_out,"The dynamic output resistance in k ohm is");

diff --git a/2444/CH4/EX4.11/ex4_11.sce b/2444/CH4/EX4.11/ex4_11.sce
new file mode 100755
index 000000000..fb654e74b
--- /dev/null
+++ b/2444/CH4/EX4.11/ex4_11.sce
@@ -0,0 +1,17 @@
+// Exa 4.11

+clc;

+clear;

+close;

+format('v',5)

+// Given data

+V_CC = 8;// in V

+I_CR_C = 0.5;// in V

+R_C = 800;// in ohm

+V_CE = V_CC - I_CR_C;// in V

+disp(V_CE,"The collector emitter voltage in V is");

+I_C = I_CR_C/R_C;// in A

+Alpha = 0.96;// unit less

+Beta = Alpha/(1-Alpha);

+I_B = I_C/Beta;// in A

+I_B = I_B * 10^6;// in µA

+disp(I_B,"The Base current in µA is");

diff --git a/2444/CH4/EX4.12/ex4_12.sce b/2444/CH4/EX4.12/ex4_12.sce
new file mode 100755
index 000000000..93da3b834
--- /dev/null
+++ b/2444/CH4/EX4.12/ex4_12.sce
@@ -0,0 +1,15 @@
+// Exa 4.12

+clc;

+clear;

+close;

+format('v',5)

+// Given data

+I_E = 5;// in mA

+I_C = 4.95;// in mA

+I_CEO = 200;// in µA

+I_B = I_E-I_C;// in mA

+Beta_dc = I_C/I_B;// unit less

+disp(Beta_dc,"The value of Beta_dc is");

+Alpha_dc = Beta_dc/(1+Beta_dc);// unit less

+I_CBO = I_CEO * (1-Alpha_dc);// in µA

+disp(I_CBO,"The collector-to-base leakage cuurent in µA is");

diff --git a/2444/CH4/EX4.13/ex4_13.sce b/2444/CH4/EX4.13/ex4_13.sce
new file mode 100755
index 000000000..820b7e599
--- /dev/null
+++ b/2444/CH4/EX4.13/ex4_13.sce
@@ -0,0 +1,24 @@
+// Exa 4.13

+clc;

+clear;

+close;

+format('v',6)

+// Given data

+I_B = 25;// in µA

+I_B = I_B * 10^-6;// in A

+I_CBO = 100;// in nA

+I_CBO = I_CBO * 10^-9;// in A

+Beta = 100;// unit less

+I_C = (Beta*I_B) + ((Beta+1)*I_CBO);// in A

+I_C= I_C*10^3;// in mA

+disp(I_C,"The value of I_C in mA is");

+I_C= I_C*10^-3;// in A

+I_E = I_C + I_B;// in A

+I_E= I_E*10^3;// in mA

+disp(I_E,"The value of I_E in mA is");

+I_E= I_E*10^-3;// in A

+Alpha = Beta/(1+Beta);// unit less

+disp(Alpha,"The value of Alpha is");

+I_CEO = I_CBO/(1-Alpha);// in A

+I_CEO = round(I_CEO *10^6);// in µA

+disp(I_CEO,"The value of I_CEO in µA is");

diff --git a/2444/CH4/EX4.14/ex4_14.sce b/2444/CH4/EX4.14/ex4_14.sce
new file mode 100755
index 000000000..33842aa20
--- /dev/null
+++ b/2444/CH4/EX4.14/ex4_14.sce
@@ -0,0 +1,22 @@
+// Exa 4.14

+clc;

+clear;

+close;

+format('v',7)

+// Given data

+R1= 4;// in ohm

+R2= 8;// in ohm

+R3= 8;// in ohm

+i1= 1;// in A (assumed)

+h11= R1+R2*R3/(R2+R3);// in ohm

+disp(h11,"The value of h11 in ohm is : ")

+i2= -1/2*i1;// in A

+h21= i2/i1;// unit less

+disp(h21,"The value of h21 is : ")

+v2= 1;// in V (assumed)

+i2= v2/(R3+R2);// in A

+v1= v2/2;// in V

+h12= v1/v2;// unit less

+disp(h12,"The value of h12 is : ")

+h22= i2/v2;// in s

+disp(h22,"The value of h22 in s is : ")

diff --git a/2444/CH4/EX4.15/ex4_15.sce b/2444/CH4/EX4.15/ex4_15.sce
new file mode 100755
index 000000000..4cba696ac
--- /dev/null
+++ b/2444/CH4/EX4.15/ex4_15.sce
@@ -0,0 +1,29 @@
+// Exa 4.15

+clc;

+clear;

+close;

+format('v',9)

+// Given data

+Ib = 20;// in µA

+Ib = Ib * 10^-6;// in A

+I_C = 1;// in mA

+I_C = I_C * 10^-3;// in A

+Vbe = 22;// in mV

+Vbe = Vbe * 10^-3;// in V

+Vce = 0;// in V

+h_ie = Vbe/Ib;// in ohm

+h_ie = h_ie * 10^-3;// in k ohm

+disp(h_ie,"The value of h_ie in k ohm is");

+h_fe = I_C/Ib;// unit less

+disp(h_fe,"The value of h_fe is");

+Ib = 0;

+Vbe = 0.25;// in mV

+Vbe = Vbe * 10^-3;// in V

+I_C = 30;// in µA

+I_C = I_C * 10^-6;// in A

+Vce = 1;// in V

+h_re = Vbe/Vce;// unit less

+disp(h_re,"The value of h_re is");

+h_oe = I_C/Vce;// in S

+h_oe = h_oe * 10^6;// in µS

+disp(h_oe,"The value of h_oe in µS is");

diff --git a/2444/CH4/EX4.16/ex4_16.sce b/2444/CH4/EX4.16/ex4_16.sce
new file mode 100755
index 000000000..f1d087ea9
--- /dev/null
+++ b/2444/CH4/EX4.16/ex4_16.sce
@@ -0,0 +1,13 @@
+// Exa 4.16

+clc;

+clear;

+close;

+format('v',6)

+// Given data

+h_fe = 50;// unit less

+h_ie = 0.83;// in k ohm

+h_ie = h_ie * 10^3;// in ohm

+h_fb = -h_fe/(1+h_fe);// unit less

+disp(h_fb,"The current gain is");

+h_ib = h_ie/(1+h_fe);// in ohm

+disp(h_ib,"The input impedance in ohm is");

diff --git a/2444/CH4/EX4.17/ex4_17.sce b/2444/CH4/EX4.17/ex4_17.sce
new file mode 100755
index 000000000..59c51215b
--- /dev/null
+++ b/2444/CH4/EX4.17/ex4_17.sce
@@ -0,0 +1,19 @@
+// Exa 4.17

+clc;

+clear;

+close;

+format('v',7)

+// Given data

+h_ie = 2600;// in ohm

+h_fe = 100;

+h_re = 0.02*10^-2;

+h_oe = 5*10^-6;// in S

+h_ic = h_ie;// in ohm

+disp(h_ic,"The value of h_ic in ohm is");

+h_fc = -(1+h_fe);

+disp(h_fc,"The value of h_fc is");

+h_rc = 1 - h_re;

+h_rc = 1;

+disp(h_rc,"The value of h_rc is");

+h_oc = h_oe;// in S

+disp(h_oc,"The value of h_oc in S is");

diff --git a/2444/CH4/EX4.18/ex4_18.sce b/2444/CH4/EX4.18/ex4_18.sce
new file mode 100755
index 000000000..0b954ae18
--- /dev/null
+++ b/2444/CH4/EX4.18/ex4_18.sce
@@ -0,0 +1,27 @@
+// Exa 4.18

+clc;

+clear;

+close;

+format('v',5)

+// Given data

+h_ie = 1000;// in ohm

+h_fe = 50;// unit less

+h_re = 2.5*10^-4;// unit less

+h_oe = 25*10^-6;// in A/V

+R_L = 10;// in k ohm

+R_L = R_L * 10^3;// in ohm

+Rs = 100;// in ohm

+Ai = -h_fe/(1 + (h_oe*R_L));// unit less

+disp(Ai,"The current gain is");

+Rin = h_ie - ( (h_re*h_fe)/(h_oe+(1/R_L)) );// in ohm

+disp(Rin,"The input resistance in ohm is");

+Av = Ai*(R_L/Rin);// unit less

+disp(Av,"The voltage gain is");

+Ais = Ai * (Rs/(Rin+Rs));// unit less

+Avs = Av*(Rin/(Rin+Rs));// unit less

+Gout = h_oe - ( (h_fe*h_re)/(h_ie+Rs) );// in S

+Rout = 1/Gout;// in ohm

+Rout = Rout * 10^-3;// in k ohm

+disp(Rout,"The output resistance in k ohm is");

+Ap = Avs*Ais;// unit less

+disp(Ap,"The power gain is");

diff --git a/2444/CH4/EX4.19/ex4_19.sce b/2444/CH4/EX4.19/ex4_19.sce
new file mode 100755
index 000000000..f45286f5b
--- /dev/null
+++ b/2444/CH4/EX4.19/ex4_19.sce
@@ -0,0 +1,29 @@
+// Exa 4.19

+clc;

+clear;

+close;

+format('v',6)

+// Given data

+h_ie = 2;// in k ohm

+h_ie = h_ie * 10^3;// in ohm

+h_re = 2*10^-4;// unit less

+h_fe = 50;// unit less

+h_oe = 20*10^-6;// in A/V

+R_L = 4;// in k ohm

+R_L = R_L * 10^3;// in ohm

+Rs = 200;// in ohm

+Ai = -h_fe/( 1+(h_oe*R_L) );// unit less

+disp(Ai,"The value of Ai is");

+Ri = h_ie - ( (h_re*h_fe)/( h_oe+(1/R_L) ) );// in ohm

+disp(Ri,"The value of Ri in ohm is");

+//Av = -h_fe/( (h_oe + (1/R_L))*Rin ) = Ai*(R_L/Rin);

+Av = Ai*(R_L/Ri);// unit less

+disp(Av,"The value of Av is");

+Gout = h_oe - ( (h_fe*h_re)/(h_ie+Rs) );// in S

+Rout = 1/Gout;// in ohm

+Rout = Rout * 10^-3;// in k ohm

+disp(Rout,"The value of Rout in  k ohm is");

+Ais = Ai * (Rs/(Ri+Rs) );// unit less

+Avs = Av * (Ri/(Ri+Rs));// unit less

+Ap = Av*Ai;// unit less

+disp(Ap,"The value of Ap is");

diff --git a/2444/CH4/EX4.2/ex4_2.sce b/2444/CH4/EX4.2/ex4_2.sce
new file mode 100755
index 000000000..beeb742da
--- /dev/null
+++ b/2444/CH4/EX4.2/ex4_2.sce
@@ -0,0 +1,32 @@
+// Exa 4.2

+clc;

+clear;

+close;

+format('v',6)

+// Given data

+delV_BE = 0.02;// in V

+delI_B = 10;// in µA

+delI_B = delI_B * 10^-6;// in A

+delI_C = 1;// in mA

+delI_C = delI_C * 10^-3;// in A

+R_C = 5;// in k ohm

+R_C = R_C * 10^3;// in ohm

+R_L = 10;// in k ohm

+R_L = R_L * 10^3;// in ohm

+Zin = delV_BE/delI_B;// in ohm

+Zin= Zin*10^-3;// in k ohm

+disp(Zin,"The input impedance in k ohm is");

+Zin= Zin*10^3;// in ohm

+Beta = delI_C/delI_B;// unit less

+disp(Beta,"The current gain is");

+Rac = (R_C*R_L)/(R_C+R_L);// in ohm

+Rac= Rac*10^-3;// in k ohm

+disp(Rac,"The AC load resistance in k ohm is");

+Rac= Rac*10^3;// in ohm

+Rin = 2;// in k ohm

+Rin = Rin * 10^3;// in ohm

+Av = Beta*(Rac/Rin);

+disp(Av,"The voltage gain is");

+Ai = 100;// unit less

+Ap = Av*Ai;// unit less

+disp(Ap,"The power gain is");

diff --git a/2444/CH4/EX4.20/ex4_20.sce b/2444/CH4/EX4.20/ex4_20.sce
new file mode 100755
index 000000000..e9ce92cd4
--- /dev/null
+++ b/2444/CH4/EX4.20/ex4_20.sce
@@ -0,0 +1,21 @@
+// Exa 4.20

+clc;

+clear;

+close;

+format('v',6)

+// Given data

+R_S = 200;// in ohm

+R_L = 1200;// in ohm

+h_ib = 24;// in ohm

+h_rb = 4*10^-4;// unit less

+h_fb = -0.98;// unit less

+h_ob = 0.6;// in µA/V

+h_ob = h_ob * 10^-6;// in A/V

+Ai = -h_fb/(1+(h_ob*R_L));// unit less

+disp(Ai,"The current gain is");

+Ri = h_ib + (h_rb*Ai*R_L);// in ohm

+disp(Ri,"The input impedance in ohm is");

+Av = round((Ai*R_L)/Ri);// unit less

+disp(Av,"The Voltage gain is");

+Ais = (Ai*R_S)/(Ri+R_S);// unit less

+disp(Ais,"The overall current gain is");

diff --git a/2444/CH4/EX4.21/ex4_21.sce b/2444/CH4/EX4.21/ex4_21.sce
new file mode 100755
index 000000000..6ff4746b9
--- /dev/null
+++ b/2444/CH4/EX4.21/ex4_21.sce
@@ -0,0 +1,13 @@
+// Exa 4.21

+clc;

+clear;

+close;

+format('v',5)

+// Given data

+g_m = 2500;// in µS

+g_m = g_m * 10^-6;// in S

+R_L = 12;// in k ohm

+R_L = R_L * 10^3;// in ohm

+//Av = -g_m*(r_d||R_D||R_L);

+Av = -g_m*R_L;

+disp(Av,"The voltage gain is");

diff --git a/2444/CH4/EX4.22/ex4_22.sce b/2444/CH4/EX4.22/ex4_22.sce
new file mode 100755
index 000000000..f2eb4ba4e
--- /dev/null
+++ b/2444/CH4/EX4.22/ex4_22.sce
@@ -0,0 +1,17 @@
+// Exa 4.22

+clc;

+clear;

+close;

+format('v',6)

+// Given data

+R_D = 5;// in k ohm

+R_D = R_D * 10^3;// in ohm

+r_d = 35;// in k ohm

+r_d = r_d * 10^3;// in ohm

+miu = 50;// amplifier factor

+g_m = miu/r_d;// in S

+Av = -g_m*( (r_d*R_D)/(r_d+R_D) );

+disp(Av,"The voltage gain is");

+Rout = (R_D*r_d)/(R_D+r_d);// in  ohm

+Rout= Rout*10^-3;// in k ohm

+disp(Rout,"The output resistance in k ohm is");

diff --git a/2444/CH4/EX4.23/ex4_23.sce b/2444/CH4/EX4.23/ex4_23.sce
new file mode 100755
index 000000000..a4d2cd393
--- /dev/null
+++ b/2444/CH4/EX4.23/ex4_23.sce
@@ -0,0 +1,25 @@
+// Exa 4.23

+clc;

+clear;

+close;

+format('v',5)

+// Given data

+V_GS = -1.0;// in V

+V_DS = 4.0;// in V

+I_DS = 1;// in mA

+I_DS = I_DS * 10^-3;// in A

+I_G = 0;// in A

+R_G = 500;// in k ohm

+R_G = R_G * 10^3;// in ohm

+V_DD = 10;// in V

+V_DS = 4;// in V

+V_G = I_G*R_G;// in V

+Vs = V_G-V_GS;// in V

+R_S = Vs/I_DS;// in ohm

+R_S= R_S*10^-3;// in k ohm

+disp(R_S,"The value of R_S in k ohm is");

+R_S= R_S*10^3;// in ohm

+// V_DD = I_DD*R_D + V_DS+ I_DS*R_S = I_DS*(R_D+R_S) + V_DS

+R_D = ((V_DD-V_DS)/I_DS)-R_S;// in ohm

+R_D = R_D * 10^-3;// in k ohm

+disp(R_D,"The value of R_D in k ohm is");

diff --git a/2444/CH4/EX4.24/ex4_24.sce b/2444/CH4/EX4.24/ex4_24.sce
new file mode 100755
index 000000000..fb00a6686
--- /dev/null
+++ b/2444/CH4/EX4.24/ex4_24.sce
@@ -0,0 +1,29 @@
+// Exa 4.24

+clc;

+clear;

+close;

+format('v',5)

+// Given data

+V_GS = -1;// in V

+V_DS = -4;// in V

+I_DS = 1;// in mA

+I_DS = I_DS * 10^-3;// in A

+g_m = 5*10^-3;// in mhos

+Rds = 20;// in k ohm

+Rds = Rds * 10^3;// in ohm

+R_S = 1;// in k ohm

+R_S = R_S * 10^3;// in ohm

+R_D = 5;// in  k ohm

+R_D = R_D * 10^3;// in ohm

+//Av = Vout/Vin  = -g_m*(r_d||R_D||R_L) = -g_m*((R_D*Rds)/(R_D+Rds));

+Av = -g_m*((R_D*Rds)/(R_D+Rds));

+disp(Av,"The voltage gain is");

+R_G = 500;// in k ohm

+R_G  = R_G * 10^3;// in ohm

+Rin = R_G;// in ohm

+Rin= Rin*10^-3;// in k ohm

+disp(Rin,"The value of Rin in k ohm is");

+Rin= Rin*10^3;// in ohm

+Rout = (R_D*Rds)/(R_D+Rds);// in ohm

+Rout= Rout*10^-3;// in k ohm

+disp(Rout,"The value of Rout in  k ohm is");

diff --git a/2444/CH4/EX4.25/ex4_25.sce b/2444/CH4/EX4.25/ex4_25.sce
new file mode 100755
index 000000000..9132a118e
--- /dev/null
+++ b/2444/CH4/EX4.25/ex4_25.sce
@@ -0,0 +1,21 @@
+// Exa 4.25

+clc;

+clear;

+close;

+format('v',5)

+// Given data

+R1 = 4;// in M ohm

+R2 = 2;// in Mohm

+R_G = (R1*R2)/(R1+R2);// in Mohm

+Zin = R_G;// in Mohm

+disp(Zin,"The input impedance in Mohm is");

+R_S = 2.5;// in k ohm

+R_S = R_S * 10^3;// in ohm

+R_L = 25;// in k ohm

+R_L =  R_L * 10^3;// in ohm

+g_m = 2500;// in µS

+g_m = g_m * 10^-6;// in S

+Zout = (R_S*(1/g_m))/(R_S+(1/g_m));// in ohm

+disp(Zout,"The output impedance in ohm is");

+Av = g_m*((R_S*R_L)/(R_S+R_L))/( 1+g_m*((R_S*R_L)/(R_S+R_L)) );// unite less

+disp(Av,"The voltage gain is");

diff --git a/2444/CH4/EX4.3/ex4_3.sce b/2444/CH4/EX4.3/ex4_3.sce
new file mode 100755
index 000000000..8c1b7d888
--- /dev/null
+++ b/2444/CH4/EX4.3/ex4_3.sce
@@ -0,0 +1,14 @@
+// Exa 4.3

+clc;

+clear;

+close;

+format('v',8)

+// Given data

+Alpha = 0.988;// unit less

+I_E = 1.2;// in mA

+I_E = I_E * 10^-3;// in A

+I_CO = 0;// in A

+I_C = Alpha*I_E + I_CO;// in A

+I_B = I_E - I_C;// in A

+I_B = I_B * 10^6;// in µA

+disp(I_B,"The base current in µA is");

diff --git a/2444/CH4/EX4.4/ex4_4.sce b/2444/CH4/EX4.4/ex4_4.sce
new file mode 100755
index 000000000..f903480cd
--- /dev/null
+++ b/2444/CH4/EX4.4/ex4_4.sce
@@ -0,0 +1,24 @@
+// Exa 4.4

+clc;

+clear;

+close;

+format('v',7)

+// Given data

+I_B = 45;// in µA

+I_B = I_B * 10^-6;// in A

+I_C = 5.45;// in mA

+I_C = I_C * 10^-3;// in A

+I_E = I_B+I_C;// in A

+I_E= I_E*10^3;// in mA

+disp(I_E,"The value of I_E in mA is");

+I_E= I_E*10^-3;// in A

+Alpha = I_C/I_E;// unit less

+disp(Alpha,"The value of Alpha is");

+format('v',5)

+Beta = I_C/I_B;// unit less

+disp(Beta,"The value of Beta is");

+I_C = 10;// in mA

+I_C = I_C * 10^-3;// in A

+I_B = I_C/Beta;// in A

+I_B = I_B * 10^6;// in µA

+disp(I_B,"The required base current in µA is");

diff --git a/2444/CH4/EX4.5/ex4_5.sce b/2444/CH4/EX4.5/ex4_5.sce
new file mode 100755
index 000000000..344c32829
--- /dev/null
+++ b/2444/CH4/EX4.5/ex4_5.sce
@@ -0,0 +1,11 @@
+// Exa 4.5

+clc;

+clear;

+close;

+format('v',8)

+// Given data

+delV_EB = 200;// in mV

+delI_E = 5;// in mA

+// Dynamic input resistance for CB configuration,

+r_in = delV_EB/delI_E;// in ohm

+disp(r_in,"The dynamic input resistance of transistor in ohm is");

diff --git a/2444/CH4/EX4.6/ex4_6.sce b/2444/CH4/EX4.6/ex4_6.sce
new file mode 100755
index 000000000..09fe07923
--- /dev/null
+++ b/2444/CH4/EX4.6/ex4_6.sce
@@ -0,0 +1,15 @@
+// Exa 4.6

+clc;

+clear;

+close;

+format('v',5)

+// Given data

+R_L = 4;// in k ohm

+R_L = R_L * 10^3;// in ohm

+V_across_RL = 3;// in V

+I_C = V_across_RL/R_L;// in A

+I_C = I_C * 10^3;// in mA

+Alpha = 0.96;// unit less

+I_E = I_C/Alpha;// in mA

+I_B = I_E - I_C;// in mA

+disp(I_B,"The base current in mA is");

diff --git a/2444/CH4/EX4.7/ex4_7.sce b/2444/CH4/EX4.7/ex4_7.sce
new file mode 100755
index 000000000..92e5204ab
--- /dev/null
+++ b/2444/CH4/EX4.7/ex4_7.sce
@@ -0,0 +1,14 @@
+// Exa 4.7

+clc;

+clear;

+close;

+format('v',8)

+// Given data

+I_E = 3;// in mA

+I_CO = 10;// in µA

+I_CO = I_CO * 10^-3;// in mA

+Alpha = 0.98;// unit less

+I_C = (Alpha*I_E) + I_CO;// in mA

+disp(I_C,"The collector current in mA is");

+I_B = I_E - I_C;// in mA

+disp(I_B,"The base current in mA is");

diff --git a/2444/CH4/EX4.8/ex4_8.sce b/2444/CH4/EX4.8/ex4_8.sce
new file mode 100755
index 000000000..2d21b1513
--- /dev/null
+++ b/2444/CH4/EX4.8/ex4_8.sce
@@ -0,0 +1,14 @@
+// Exa 4.8

+clc;

+clear;

+close;

+format('v',6)

+// Given data

+I_E = 2;// in mA

+I_C = 1.97;// in mA

+I_B = I_E-I_C;// in mA

+disp(I_B,"The base current in mA is");

+I_CO = 12.5;// in µA

+I_CO = I_CO * 10^-3;// in mA

+Alpha = (I_C-I_CO)/I_E;// unit less

+disp(Alpha,"The current gain is");

diff --git a/2444/CH4/EX4.9/ex4_9.sce b/2444/CH4/EX4.9/ex4_9.sce
new file mode 100755
index 000000000..2fe530a6b
--- /dev/null
+++ b/2444/CH4/EX4.9/ex4_9.sce
@@ -0,0 +1,12 @@
+// Exa 4.9

+clc;

+clear;

+close;

+format('v',8)

+// Given data

+delV_BE = 250;// in mV

+delV_BE = delV_BE * 10^-3;// in V

+delI_B = 1;// in mA

+delI_B = delI_B * 10^-3;// in A

+r_in = delV_BE/delI_B;// in ohm

+disp(r_in,"The dynamic input resistance in ohm is");