Question

In p – n –p transistor circuit, the collector current is 10 m A. if 90%oftheholes reach the collector, the emitter and base currents respectively are.

• A. 10 mA, 1 mA
• B. 22 mA, 11 mA
• C. 11 mA, 1 mA
• D. 20 mA, 10 mA

Answer 1

Answer: (C)

11 mA, 1 mA

Answer 2

: the voltage gain of a common emitter amplifier

$A_{v} = - \frac{\beta R_{o}}{R_{i}}or\frac{V_{o}}{V_{i}} = - \frac{\beta R_{C}}{R_{B}}$

Output voltage

$\therefore V_{o} = - \frac{\beta R_{C}V_{i}}{R_{B}} = - \frac{50 \times 5 \times 0.01}{1} = - 2.5V$