Physics - Semiconductors Question with Solution | TestHub

Given $I_C=28$ mA.

Since $80$ percent of the electrons emitted reach the collector, the collector current is given by:

$I_C=\frac{80}{100}{I}_E$

$28=0.8I_E$

$I_E=\frac{28}{0.8}=35$ mA

The relation between emitter, base, and collector currents is:

$I_E=I_B+I_C$

$I_B=I_E-I_C$

$I_B=35-28=7$ mA

Answer: $7$ mA