clc NE=1*10^17 disp("NE = "+string(NE)+" /cm^3") //initializiation the value of doping concentration of emitter in the NPN transistor. NB=10^15 disp("NB = "+string(NB)+" /cm^3") //initializiation the value of doping concentration of base in the NPN transistor. WE=0.6*10^-4 disp("WE = "+string(WE)+" cm") //initializiation the value of one of parametre of the transistor. WB=0.8*10^-4 disp("WB = "+string(WB)+" cm") //initializiation the value of one of parametre of the transistor. no=1.5*10^10 disp("no = "+string(no)+"cm^-3") //initializing the value of intrinsic carrier concentration. e=1.6*10^-19 disp("e = "+string(e)+" columns") //initializiation the value of electronic charge DE=15 disp("DE = "+string(DE)+" cm^2/s") //initializiation the value of one of parametere of the transistor. DB=20 disp("DB = "+string(DB)+" cm^2/s") //initializiation the value of one of parametere of the transistor. tE=0.2*10^-6 disp("tE = "+string(tE)+" s") //initializiation the value of one of parametere of the transistor. tB=0.1*10^-6 disp("tB = "+string(tB)+" s") //initializiation the value of one of parametere of the transistor. Vbe=0.60 disp("Vbe = "+string(Vbe)+" V") //initializiation the value of base emitter voltage . VT=0.0259 disp("VT = "+string(VT)+" V") //initializiation the value of threshold voltage. Jro=2*10^-8 disp("Jro = "+string(Jro)+" A/cm^2") //initializiation the value of recombination current density. LE=(sqrt(DE*tE)) disp("LE=(sqrt(DE*tE)))="+string(LE)+" cm")//calculation LB=(sqrt(DB*tB)) disp("LB=(sqrt(DB*tB)))="+string(LB)+" cm")//calculation pEO=(no^2/NE) disp("Number of Majority holes in the emitter,pEO=(no^2/NE) )="+string(pEO)+" /cm^3")//calculation nBO=(no^2/NB) disp("Number of Majority holes in the base,nBO=(no^2/NB))="+string(nBO)+" /cm^3")//calculation Y=(1+(((NB*DE*LB)/(NE*DB*LE))*((tanh(WB/LB)/tanh(WE/LE)))))^(-1) disp("Emitter injection efficiency,Y=(1+((NB*DE*LB)/(NE*DB*LE)*(tanh(WB/LB)/tanh(WE/LE)))) )="+string(Y))//calculation Bt=(cosh(WB/LB))^-1 disp("Base transport factor,Bt=(cosh(WB/LB))^-1)="+string(Bt))//calculation Jo=((e*DB*nBO)/(LB*tanh(WB/LB))) disp("Reverse saturation current Density,Jro=((e*DB*nBO)/(LB*tanh(WB/LB))))="+string(Jo)+"A/cm^2")//calculation delta=(1+((Jro/Jo)*(exp((-Vbe)/(2*VT)))))^-1 disp("delta(recombination factor)=(1+((Jro/Jo)*(exp((-Vbe)/(2*VT)))))^-1)="+string(delta)+" A")//calculation a=Bt*delta*Y disp("common base current amplification factor,(alpha=Bt*delta*Y)="+string(a))//calculation B=(a/(1-a)) disp("common emitter current amplification factor,Beta=(a/(1-a)))="+string(B))//calculation //the value of NE provided in the question is different than used in the solution . //I have used the value (while solving) provided in the question (i.e NE=10^17/cm^3).