For a common emitter transistor amplifier, the audio signal voltage across the collector resistance of `2kOmega` is 2V. If the current amplification factor of the transistor is 100, calculate (i) input signal voltage (ii) base current and (iii) power gain. Given that the value of the base resistance is `1kOmega`.

Explanation

Here, `R_(C) =2kOmega=2000Omega`,
`R_(B) =1kOmega=1000Omega`,
`beta=100, V_(0)=2V`.
(i) Voltage gain, `A_(V)=V_(0)/V_(i)=beta R_(0)/R_(i)=beta R_(C)/R_(B)`
or `V_(i)=(V_(0)R_B)/(betaR_C)=(2xx1000)/(100xx2000)=0.01V`
`beta=I_C/I_B=(V_(0)//R_C)/I_B`
or `I_=V_(0)/(betaxxR_C)=2/(100xx2000)=10^(-5)A=10muA`
(iii) Power gain, `A_(P)=beta^(2)R_(0)/R_(i)=beta^(2)R_C/R_B`
`=(100)^(2)xx2000/1000=20,000`