Question

In a transistor, the change in base current from $100$$\mu$A to $125$$\mu$A causes a change in collector current from $5mA$ to $7.5mA$, keeping collector-to-emitter voltage constant at $10$, current gain is

• A. $200$
• B. $100$
• C. $50$
• D. $25$

Answer 1

The correct option is B $100$

Current gain = $\frac{\Delta I_C}{\Delta I_B}$ when $V_{CE}$ is constant.

$=\frac{2.5\times {10}^{-3}}{25\times {10}^{-6}}=0.1\times {10}^3=100$

[$\Delta I_B=125\mu A-100\mu A=25\mu A,\Delta I_C=7.4mA-5mA=2.5mA$]