Semiconductor Electronics Materials Devices and Simple Circuits - Result Question 79
81. The current gain for a transistor working as common-base amplifier is 0.96 . If the emitter current is $7.2 mA$, then the base current is
(a) $0.29 mA$
(b) $0.35 mA$
(c) $0.39 mA$
(d) $0.43 mA$
[1996]
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Answer:
Correct Answer: 81. (a)
Solution:
- (a) Current gain $(\alpha)=0.96$
$I_e=7.2 mA$
$\frac{I_c}{I_e}=\alpha=0.96$
$I_c=0.96 \times 7.2 mA=6.91 mA$
$I_e=I_c+I_b$
$\stackrel{e}{\Rightarrow} I_b^{c}=I_e-I_c=7.2-6.91=0.29 mA$
