Question

In a common base configuration $I_e=1mA;\alpha =0.95$, the value of base current is

• A. $1.95mA$
• B. $0.05mA$
• C. $1.05mA$
• D. $0.95mA$

Answer 1

The correct option is B $0.05mA$

Given :

$I_e=1mA$,

$\alpha =0.95$

We know,

$\alpha =\frac{I_c}{I_e}$

$I_c=\alpha I_e$

$I_c=\left(0.95\right)\left(1\right)$

$I_c=0.95mA$

For transistor,

$I_b=I_e-I_c$

$I_b=1-0.95$

$I_b=0.05mA$