Q. In a power amplifier the collector current flows for 270° of the input cycle. The operations is

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Q. An amplifier has input impedance of 4 kΩ and output impedance of 80 kΩ. It is used in negative feedback circuit with 10% feedback. If open loop gain is 90, the closed loop input and output impedances are

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Q. In a negative feedback amplifier A = 100, β = 0.04 and Vs = 50 mV, then feedback will be

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Q. A voltage doubler circuit is fed by a voltage Vm sin ωt. The output voltage will be nearly 2 Vm only if

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Q. The purpose of connecting a coupling capacitor in the output circuit of an amplifier is

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Q. A full wave rectifier circuit using centre tapped transformer, the input frequency 50 Hz. The frequency of output is

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Q. If the midband gain of an amplifier is 40 dB, the gain at half power frequency is

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Q. It is desired to reduce distortion in an amplifier from 8% to 2% by using 5% negative feedback. The open and closed loop gains respectively are

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Q. An ideal op-amp requires

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Q. A feedback network to be used with an amplifier to provide oscillation is tested and found to give an output of 0.124 V with a 0.5 V input. What percentage negative feedback should be introduced to the amplifier so that linear oscillations result?

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Q. The advantage of Weinbridge oscillator over the phase shift oscillator is that oscillator the frequency may be varied over a range of

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Q. An inverting amplifier has R1 = 10 kΩ, and Rf = 150 kΩ then the O/P voltage, if input voltage Vi = 1 volt.

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Q. Consider the following statements:

A totem pole configuration used in the output stage if an op-amp has the advantage of using

1. Only n-p-n BJTs
2. Complementary symmetrical pair of transistors
3. Only one transistor

Which of these statements is/are correct?

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Q. Assertion (A): An op-amp amplifier can amplify dc signal

Reason (R): An op-amp amplifier is a direct coupled amplifier

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Q. The most common method for biasing a JFET is

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Q. The h parameter equivalent circuit of BJT has one voltage source and one current source.

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Q. In an RC-coupled amplifier for improving the low frequency response

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Q. The minimum gate source voltage that creates the n-type inversion layer is called

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Q. At midband frequencies the coupling capacitor in RC coupled CE amplifier may be considered as

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Q. An engineer designs an amplifier to have a voltage gain of 60, but when constructed it only had a gain of 50. What percentage of feedback will cause oscillations?

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