Question

A transistor is connected in common emitter (CE) configuration. The collector supply is $8V$ and the voltage drop across a resistor of $800 \, \Omega$ in the collector circuit is $0.8V$ . If the current gain factor $\left(\alpha \right)$ is $0.96$ , then the change in the base current is

• A. $\frac{1}{24} \, mA$
• B. $\frac{1}{12} \, mA$
• C. $\frac{1}{6} \, mA$
• D. $\frac{1}{3} \, mA$

Answer 1

Answer: (A)

According to the question :
$\alpha =0.96$
Amplification factor, $\beta =\frac{\alpha }{1 - \alpha }=\frac{0.96}{1 - 0.96}=24$
Change in collector current, $\Delta I_{C}=\frac{0.8}{800}=10^{- 3}A$
Change in base current, $\Delta I_{B}=\frac{\Delta l_{C}}{\beta }=\frac{10^{- 3}}{24}A$
$=\frac{1}{24}mA$