Question

If a change of $100$$\mu A$ in the base current of an n-p-n transistor causes a change of $10mA$ in the collector current, the ac current gain of the transistor is

• A. $10$
• B. $100$
• C. $1000$
• D. $10000$

Answer 1

The correct option is B $100$

Given that:
$\Delta I_b=100\mu A={10}^{-4}$
$\Delta I_c=10mA={10}^{-2}$
The ac current gain of the transistor is the ratio of output current to the input current.
Hence, $\alpha =\frac{\Delta I_c}{\Delta I_b}$

$\alpha =\frac{{10}^{-2}}{{10}^{-4}}={10}^2=100$