Question

The transfer characteristic curve of a transistor, having input and output resistance $100 \, \Omega$ and $100 \, k\Omega$ 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 $= A _{ V } \times \beta=50 \times 5 \times 10^{4}=2.5 \times 10^{6}$