Question

For a common base amplifier, current gain is $60$. If the emitter current is $6.6mA$, the collector current is:

• A. $0.108mA$
• B. $6.492mA$
• C. $1.1mA$
• D. $3.3mA$

Answer 1

Answer: (B)

$6.492mA$

Given:
$\beta =60$
$I_E=6.6mA$
Now,
$\alpha =\frac{\beta }{1+\beta }$
$\alpha =\frac{60}{1+60}$
$\alpha =\frac{60}{61}=0.9836$
Also,
$\alpha =\frac{I_c}{I_e}$
$\Rightarrow I_c=\alpha I_e$
$I_c=\left(0.9836\right)\left(6.6\right)=6.492mA$