Semiconducting Devices Question 95
Question: In a PNP transistor working as a common-base amplifier, current gain is 0.96 and emitter current is 7.2 mA. The base current is
[AFMC 2002; Pb. PET 2002]
Options:
A) 0.4 mA
B) 0.2 mA
C) 0.29 mA
D) 0.35 mA
Show Answer
Answer:
Correct Answer: C
Solution:
$ \alpha =\frac{i _{c}}{i _{e}} $ =0.96 and ie = 7.2 mA
$ \Rightarrow i _{c}=0.96\times i _{e} $ = 0.96 x 7.2 = 6.91 mA
$ \therefore i _{e}=i _{c}+i _{b} $
Therefore 7.2 = 6.91 + ib
Therefore ib = 0.29 mA.
