Question

Two amplifiers are connected in series. The first amplifier has a voltage gain of $10$ while the second one has voltage gain of $20$. If the input signal is $0.01 \,V$, calculate the voltage of the output $AC $ signal.

• A. 2V
• B. 3V
• C. 4V
• D. 5V

Answer 1

Answer: (A)

The given, $A_{1}=10$,
$A_{2}=20 $
$V_{i}=0.001 $
$V_{0}=?$
Total voltage gain,
$A_{v}=A_{1} \times A_{2}$
$=10 \times 20=200$
We know that, Voltage gain
$A_{v}=\frac{\text { Output voltage }\left(V_{0}\right)}{\text { Input signal voltage }\left(V_{i}\right)}$
Output voltage $\left(V_{0}\right)=A_{v} \times V_{i}$
$=200 \times 0.01=2 V$