Consider the circuit arrangnent shown in Fig. for studying input and output characteristics of npn transistor in CE configuration.
Select the values of `R_` and `R_` for a transistor whose `V_(BE)=0.7V`, so that the transistor is operating at point Q as shown in the characteristics shown in Fig.
Given that the input impedance of the transistor is very small and `V_(C C)=V_(BB)=16V`, also find the voltage gain and power gain of circuit making appropriate assumptions.

Explanation

`V_(CE)=8V, I_=4xx10^(-3)A, I_=30muA=30xx10^(-6)A, V_(BE)=0.7V, R_(i)=0, V_(C C)=V_(BB)=16V`.
From the input circuit `V_(BB)=I_B R_B+V_(BE) or 16=(30xx10^(-6))R_B+0.7`
or `15.3=(30xx10^(-6))R_B or R_B=15.3/(30xx10^(-6))=5.1xx10^(5)Omega=510kOmega`
From the output circuit `V_(C C)=I_C R_C+V_(CE) or 16=(4xx10^(-3))R_C+8`
or `8=(4xx10^(-3))R_C or R_C=8/(4xx10^(-3))=2xx10^(3)Omega=2kOmega`
`beta=I_C/I_B=(4xx10^(-3))/(30xx10^(-6))~~133`
Voltage gain, `A_(v)=-betaR_C/R_B=-133xx(2xx10^(3))/(5.1xx10^(5))=-0.52`
Power gain, `A_(P)=betaxxA_(v)=133xx0.52~~69`