Semiconductor Electronics Materials Devices and Simple Circuits - Result Question 71
73. A transistor is operated in common-emitter configuration at $V_c=2 V$ such that a change in the base current from $100 \mu A$ to $200 \mu A$ produces a change in the collector current from $5 mA$ to $10 mA$. The current gain is
[2009]
(a) 100
(b) 150
(c) 50
(d) 75
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Answer:
Correct Answer: 73. (c)
Solution:
- (c) $\Delta I_E=\Delta I_B+\Delta I_C$
$\beta=\frac{\Delta I_C}{\Delta I_B}$
$\Delta I_C=(10-5) 10^{-3}$
$=5 \times 10^{-3} A$
$\Delta I_B=(200-100) 10^{-6}$
$=100 \times 10^{-6} A$
$\beta=\frac{5 \times 10^{-3}}{100 \times 10^{-6}}=\frac{5}{100} \times 1000=50$
