In a common emitter transistor transistor amplifier, the audio signal voltage across the collector is `3kOmega`. If current gain is 100 and the base resistance is `2kOmega`, the voltage and power gain of the amplifier are

Options

A. 200 and 1000
B. 15 and 200
C. 150 and 15000
D. 20 and 2000

Answer

C

Explanation

Collector current`i_(c)=(V)/(R)=(3)/(3xx10^(3))=(10^(-3))/(100)=10^(-3)A`
Now base `current_(B)=(i_(C))/(B)=(10^(-3))/(100)=10^(-5)A`
As, `voltage V_(in)=i_(B)R_(B)rArrV_(in)=10^(-15)xx2xx10^(10^(3))`
`=2xx10^(-2) volts`
`So, voltage gain `A_(v)=(V_(out))/(V_(in))=(3)/(2xx10^(-2))=150`
Power gain `=A_(V)xxbeta=150xx100=15000`