A transistor is operated in common emitter configuration at V_C=2 ~V such that a change in the base current from 100 μ A to 300 μ A produces a change in the collector current from 10 ~mA to 20 ~mA . The current gain is

Correct answer: (D) 50. β=(Δ I_C)/(Δ I_B)=((20-10) mA)/((300-100) mA)=frac10 × 10^-3200 × 10^-6=50

Q105 / 200 · NEET 2011 (Screening) · Physics

A transistor is operated in common emitter configuration at $V_C=2 \mathrm{~V}$ such that a change in the base current from $100 \mu \mathrm{A}$ to $300 \mu \mathrm{A}$ produces a change in the collector current from $10 \mathrm{~mA}$ to $20 \mathrm{~mA}$. The current gain is

$\beta=\frac{\Delta I_C}{\Delta I_B}=\frac{(20-10) \mathrm{mA}}{(300-100) \mathrm{mA}}=\frac{10 \times 10^{-3}}{200 \times 10^{-6}}=50$

Hence, the correct answer is option: 'D'.