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 $0.01V$, 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 $\left(V_0\right)=A_v\times V_i$
$=200\times 0.01=2V$