Question

For a transistor the current amplification factor is $0.8$. The transistor is connected in common emitter configuration, the change in collector current when the base current changes by $6mA$ is:

• A. $6mA$
• B. $4.8mA$
• C. $24mA$
• D. $8mA$

Answer 1

The correct option is C $24mA$

Given that:
$\alpha =0.8$
$I_b=6mA$
Now,
$\beta =\frac{\alpha }{1-\alpha }$

$\beta =\frac{0.8}{1-0.8}$

$\beta =\frac{0.8}{0.2}=4$

Since, $\beta =\frac{I_c}{I_b}$

$\Rightarrow I_c=\beta I_b$
$\therefore I_c=\left(4\right)\left(6\right)=24mA$