Question

In a N-P-N transistor about ${10}^{10}$ electrons enter the emitter in $2\mu s$, when it is connected to a battery. Then $I_E=$ ________ $\mu A$

• A. $200$
• B. $400$
• C. $800$
• D. $1600$

Answer 1

The correct option is C $800$

Charge flown $Q=ne={10}^{10}\times 1.6\times {10}^{-19}C=1.6\times {10}^{-9}C$
Emitter current $I_E=\frac{Q}{t}$
$I_E=\frac{1.6\times {10}^{-9}}{2\times {10}^{-6}}=0.8\times {10}^{-3}A=800\mu A$