Q 12-14-106JEE MainJEE Main 2022 (24 Jun, Shift 1)Medium
A transistor is used in common-emitter mode in an amplifier circuit. When a signal of $10\ \text{mV}$ is added to the base-emitter voltage, the base current changes by $10\ \mu\text{A}$ and the collector current changes by $1.5\ \text{mA}$. The load resistance is $5\ \text{k}\Omega$. The voltage gain of the transistor will be ______.
Numerical value type. Enter your answer.
Answer: 750
Current gain $\beta = \dfrac{1.5\ \text{mA}}{10\ \mu\text{A}} = 150$; input resistance $r_i = \dfrac{10\ \text{mV}}{10\ \mu\text{A}} = 1\ \text{k}\Omega$.
$$A_V = \beta\frac{R_L}{r_i} = 150\times\frac{5}{1} = 750$$
Solution by Sreeraj P, M.Sc Physics