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.

Let A1 = 10 (Voltage gain of the first amplifier)


and A2 = 20 (Voltage gain of the second amplifier)


Vi = 0.01 V (Input signal voltage)


Let, Output AC signal voltage = Vo


We have the relation:


V0 = A × Vi


Output after the first stage VO1 = A1 × Vi


Then, output after the 2nd stage VO2 = VO1 × A2 = Vi × A1 × A2


Hence, the final output = VO = 20 × 10 × 0.01 = 2 Volts


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


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