Question

The $ac$ current gain of a transistor is $120$. What is the change in the collector current in the transistor whose base current changes by $100 \,\mu A$?

• A. $6\,mA$
• B. $12\,mA$
• C. $3\,mA$
• D. $24\,mA$

Answer 1

Answer: (B)

Here, $I_B = 100 \,\mu A $
$= 100 \times 10^{-6}\, A, \beta_{ac} = 120$
Using, $\beta_{ac} = \frac{\Delta I_C}{\Delta I_B}$
$\therefore 120 = \frac{\Delta I_C}{100 \times 10^{-6}}$
Change in collector current,
$\Delta I_C = 120 \times 100 \times 10^{-6}$
$ = 12\times 10^{-3}$
$= 12\,mA$