Question

A CE amplifier has a voltage gain 50, an input impedance of 1000 ohm 1 and an output impedance of 200 ohm. The power gain of the amplifier will be

Options

• 24 dB

• 41 dB

• 250 dB

• 12500 dB

Answer 1

41 dB

Explanation:

Power gain in dB = `10 log P_0/P_1`

= `10 log  (v_0^2/R_0)/(v_1^2/R_1)`

= `10 log  ((vo)/(vi))^2 xx (Ri)/(Ro)`

= `log 10 (50)^2 xx 1000/20 = 10 log 12500`

= `10 xx 4.096` g

= 41 dB.