Question

The value of current gain $\alpha$ of a transistor is $0.98$. The value of $\beta$ will be

• A. $490$
• B. $4.9$
• C. $59$
• D. $49$

Answer 1

The correct option is D $49$

$\alpha =\frac{I_c}{I_e}$ and $\beta =\frac{I_c}{I_b}$
$[I_c,I_b$ and $I_e$ are collector, base and emitter current.
$I_e=I_c+I_b$ a$\Rightarrow$ $\frac{I_e}{I_c}=1+\frac{I_b}{I_c}$
$\frac{!}{\alpha }=1+\frac{1}{\beta }$ $\Rightarrow$ $\beta =\frac{\alpha }{1-\alpha }=\frac{0.98}{1-0.98}$
$=\frac{0.98}{0.02}=49$