Question

Two amplifiers are connected one after the other in series (cascaded). The first amplifier has a voltage gain of 10 and the second has a voltage gain of 20. If the input signal is 0.01 volt, calculate the output ac signal.

Answer 1

Voltage gain of the first amplifier, V₁ = 10

Voltage gain of the second amplifier, V₂ = 20

Input signal voltage, V_i = 0.01 V

Output AC signal voltage = V_o

The total voltage gain of a two-stage cascaded amplifier is given by the product of voltage gains of both the stages, i.e.,

V = V₁ × V₂

= 10 × 20 = 200

We have the relation:

`V = V_0/V_1`

V₀ = V × V_i

= 200 × 0.01 = 2 V

Therefore, the output AC signal of the given amplifier is 2 V.