Question

In a common emitter (CE) amplifier having a voltage gainG, the transistor used has transconductance 0.03 mho and current gain 25. If the above transistor is replaced with another one with transconductance 0.02 mho and current gain 20, the voltage gain will

2/3 G

1.5 G

1/3 G

5/4 G

Name: Wired Faculty - The Best Learning App
Rating: 4.6 (1864 reviews)

Solution

2/3 G

As space straight A subscript straight v space equals straight beta straight R subscript straight L over straight R subscript straight i space open square brackets therefore space straight g subscript straight m equals fraction numerator increment straight l subscript straight c over denominator increment straight V subscript straight B end fraction close square brackets Or straight G space equals space open parentheses straight beta over straight R subscript straight i close parentheses straight R subscript straight L space open square brackets therefore space straight g subscript straight m space equals space straight beta over straight R subscript straight i close square brackets rightwards double arrow space straight G space equals straight g subscript straight m straight R subscript straight L rightwards double arrow space straight G proportional to space straight g subscript straight m therefore space straight G subscript 2 over straight G subscript 1 space equals straight g subscript straight m subscript 1 end subscript over straight g subscript straight m subscript 2 end subscript rightwards double arrow space straight G subscript 2 space equals space fraction numerator 0.02 over denominator 0.03 end fraction straight x space straight G therefore space Voltage space gain space straight G subscript 2 space equals space 2 over 3 straight G

For Daily Free Study Material Join wiredfaculty