Consider an n – p – n transistor amplifier in common emitter configuration. The current gain in the transistor is 100. If the collector current changes by 1 mA. What will be the change in emitter current?

1.01 mA

Here, $β =100, ΔI_C =1mA$

As $α=\frac{β}{1+β}=\frac{100}{101}$

$α=\frac{ΔI_C}{ΔI_E}$ or $\frac{100}{101}=\frac{1mA}{ΔI_E}$

$∴I_E =1.01mA$