Question

A transistor is used as a common emitter amplifier with a load resistance 2 KΩ. The input resistance is 150 Ω. Base current is changed by 20 µA which results in a change in collector current by 1.5 mA. The voltage gain of the amplifier is ______. 

विकल्प

• 900

• 1000

• 1100

• 1200

Answer 1

A transistor is used as a common emitter amplifier with a load resistance 2 KΩ. The input resistance is 150 Ω. Base current is changed by 20 µA which results in a change in collector current by 1.5 mA. The voltage gain of the amplifier is 1000.

Explanation:

Voltage gain = `"V"_"o"/"V"_"i"=("R"_"o"xx"I"_"c")/("R"_"i"xx"I"_"B")` 

= `(2000xx1.5xx10^-3)/(150xx20xx10^-6)`

= `3/(3000xx10^-6)`

= 1000