Amplifiers
An Amplifier is an electronic device or circuit which is used to increase the magnitude of the signal applied to its input.
Gain of an Amplifier:- Voltage gain (A$_v$) = $\dfrac{\mathrm{Output\ voltage}}{\mathrm{Input\ voltage}}$
- Current gain: (A$_i$) = $\dfrac{\mathrm{Output\ current}}{\mathrm{Input\ current}}$
- Power gain = A$_v$ $\times$ A$_i$
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As compared to FET, BJT has ________ input impedance and ________ output impedance. (UPPCL JE Paper 5- Nov 2016)
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An Amplifier circuit of voltage gain 100 gives 10V output, the value of input voltage is: (VSSC ISRO Tech B Dec 2012)
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The output voltage of a voltage amplifier is found to decrease by 20% when a load resistance of 1 K$\Omega$ is connected. What is the output resistance of the amplifier? (ISRO VSSC Tech Asst Electronics 2019)
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The power input to an amplifier is 2 $\mu$W. The power gain of the amplifier is 40 dB. The output power of amplifier is: (LPSC ISRO Tech Asst Electronics Feb 2020)
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The efficiency of a class B push-pull amplifier is: (URSC ISRO Tech B Nov 2016)
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In an amplifier, the signal handling capacity will be high when the operating point is selected: (RSMSSB JE Elec Nov 2020)
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Negative feedback in an amplifier: (BSNL JE TTA Sep 2016 Shift I)
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Find P$_{in}$ for an amplifier with a power gain of 20 and an output power of 1 W. (NLC GET ECE Nov 2020)
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Overmodulation of transmitter signal is corrected by the adjustment of the: (BSNL JE (TTA) Sep 2016 Shift I)
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When amplifiers are cascaded: (IPRC ISRO Tech Electronics Aug 2016)