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 200 μ A produces a change in the collector current from 5 ~mA to 10 ~mA . The current gain is

Correct answer: A. 50 aligned Δ I_ B & =100 μ A Δ I_ C & =5 mA β& = Δ I_ C Δ I_ B = 5 × 10^ -3 100 × 10^ -6 =50 aligned

NEET 2009

NEET 2009 · Physics · Semiconductors

A transistor is operated in common-emitter configuration at V_ C =2...

A transistor is operated in common-emitter configuration at

\mathrm{V}_{\mathrm{C}}=2 \mathrm{~V}

such that a change in the base current from

100 \mu \mathrm{A}

200 \mu \mathrm{A}

produces a change in the collector current from

5 \mathrm{~mA}

10 \mathrm{~mA}

. The current gain is :

A. 50

\begin{aligned} \Delta \mathrm{I}_{\mathrm{B}}& =100 \mu \mathrm{A}\\ \Delta \mathrm{I}_{\mathrm{C}}& =5 \mathrm{ mA}\\ \beta& =\frac{\Delta \mathrm{I}_{\mathrm{C}}}{\Delta \mathrm{I}_{\mathrm{B}}}=\frac{5 \times 10^{-3}}{100 \times 10^{-6}}=50 \end{aligned}