Three amplifiers with voltage gains 10,20 and 30 are connected in series. If the input signal has a peak…
Three amplifiers with voltage gains 10,20 and 30 are connected in series. If the input signal has a peak value of \(1 \mathrm{mV}\) then the peak value of the output voltage is
\(6 \mathrm{~V}\)
\(60 \mathrm{~V}\)
\(0.6 \mathrm{~V}\)
\(0.06 \mathrm{~V}\)
Solution
Given, voltage gains of three amplifiers,
\(A_1=10, A_2=20 \text { and } A_3=30\)
peak value of input signal
\(V_i=1 \mathrm{mV}=10^{-3} \mathrm{~V}\)
Total gain of three amplifiers connected in series is given by
\(A=A_1 \times A_2 \times A_3=10 \times 20 \times 30 \Rightarrow A=6000\)
But, \(A=\frac{V_0}{V_{\text {in }}} \Rightarrow V_0=A \times V_{\text {in }}=6000 \times 10^{-3}=6 \mathrm{~V}\)