Question

The transfer characteristic curve of a transistor, having input and output resistance $100\Omega$ and $100k\Omega$ respectively, is shown in the figure. The voltage and power gain, are respectively:

• A. $5\times 10^4,2.5\times 10^6$
• B. $2.5\times 10^4,2.5\times 10^6$
• C. $5\times 10^4,5\times 10^6$
• D. $5\times 10^4,5\times 10^5$

Answer 1

Answer: (A)

Current gain $(\beta )=\frac{\Delta I_C}{\Delta I_B}=\frac{5\times 10^{-3}}{100\times 10^{-6}}=50$
Voltage gain $\left(A_V\right)=\beta \left(\frac{R_{\text{out }}}{R_{\text{in }}}\right)=50\times \frac{100\times 10^3}{100}=5\times 10^4$
Power gain $=A_V\times \beta =50\times 5\times 10^4=2.5\times 10^6$