Question

In an n-p-n transistor circuit, the collector current is $10mA$. If $90\%$ of the electrons emitted reach the collector, then

• A. the emitter current , the will be $9mA$
• B. the base current will be $1mA$
• C. the emitter current will be $11.11mA$
• D. The base current will be $1.11mA$

Answer 1

Answer: (C), (D)

The correct options are
C the emitter current will be $11.11mA$
D The base current will be $1.11mA$

Given: $I_c=10mA$
Since, 90% of the electrons emitted reach the collector.

$I_e\left(\frac{90}{100}\right)=I_c$

$\left(0.9\right)I_e=I_c$

$I_e=\frac{I_c}{0.9}$

$I_e=\frac{10}{0.9}=11.11mA$

For transistors:
$I_e=I_b+I_c$
$I_b=I_e-I_c$
$I_b=11.11-10=1.11mA$