Question

The current gain of a transistor in the common base mode is $0.9$. If the change in the emitter current is $5mA$, the change in the collector current will be

• A. $4mA$
• B. $4.5mA$
• C. $5.6mA$
• D. $0mA$

Answer 1

The correct option is B $4.5mA$

Current again
$=\frac{\text{small change in collector current}\left(△i_c\right)}{\text{small change in emitter current}\left(△i_e\right)}$
$0.9=\frac{△i_c}{5}$
$\Rightarrow △i_e=0.9\times 5=4.5mA$.