Question

What is the total voltage gain of a cascading transistor amplifier if the gain of first stage is 4 and the gain of the second stage is 10?

(a) 0.4

(b) 4

(c) 40

(d) 2.5

This question was addressed to me at a job interview.

Question is taken from Cascading Transistor Amplifiers topic in chapter Low Frequency Transistor Amplifier Circuit of Electronic Devices & Circuits

Answer 1

Right choice is (c) 40

The explanation is: The total gain of a cascading transistor amplifier can be calculated by the formula given below. Where, AV = overall gain, AV1 = voltage gain of first stage and AV2 = voltage gain of second stage.

AV = AV1 × AV2 = 4 × 10 = 40