Objective Electronics Questions – Electrical Engineering (Page 17)

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The gain of an amplifier is expressed in dB unit because

Ait is a simple unit

Bcalculations become easy

Chuman ear response is logarithmic

Dit is the most appropriate unit

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What is the typical value of the emitter bypass capacitor Ce in a multistage amplifier?

Aabout 0.1 μF

Babout 50 μF

Cabout 100 pF

Dabout 0.01 μF

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In a multistage amplifier, if the stages have R and C component only, _____ operation is apparent.

Aclass B

Bclass C

Cclass A

Dclass AB

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In practice, what is normally varied in order to change frequency of oscillations?

Acapacitance

Binductance

Cresistance

Dimpedance

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What is the main consideration in the output stage of an amplifier?

Apower output

Bvoltage gain

Cpower gain

Dcurrent gain

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Transformer coupling provides high gain because

Atransformer is very efficient

Btransformer matching can be achieved

Ctransformer steps up the voltage

Dtransformer steps up the current

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When negative voltage feedback is applied to an amplifier, its output impedance

Aremains unchanged

Bdecreases

Cincreases

Dbecomes zero

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An LC oscillator cannot be used to produce _____ frequencies.

Ahigh

Bvery high

Caudio

Dvery low

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A transistor converts

Adc power into ac power

Bac power into dc power

Chigh resistance into low resistance

Dlow resistance into high resistance

#330📘 reviewer_appEasy

Hartley oscillator is commonly used in which of the following?

Aradio receivers

BTV receivers

Cradio transmitters

DCATV

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An oscillator oscillates due to

Anegative feedback

Bpositive feedback

Cboth positive and negative feedback

Dneither positive and negative feedback

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Generally, tuned amplifiers are operated in

Aclass C

Bclass A

Cclass B

Dclass AB

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A tuned amplifier is used in what application?

Aradio frequency

Baudio frequency

Cintermediate frequency

Dlow frequency

#334📘 reviewer_appEasy

What is the ratio of output to input impedance of a CE amplifier?

Avery low

Bvery high

Cmoderate

Dapproximately 1

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For a constant output frequency, the simplest sinusoidal oscillator circuit due to construct is _____.

Athe crystal circuit

Bthe phase-shift circuit

Cthe Colpitts circuits

Dthe Hartley circuit

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Transformer coupling introduces what type of distortion?

Aamplitude

Bfrequency

Cphase

Dintermodulation

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A pulsating dc applied to power amplifiers causes

Aburning of transistor

Bhum in the circuit

Cexcessive forward voltage

Dexcessive reverse voltage

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What is the disadvantage of impedance matching?

Ait gives distorted output

Bit requires a transformer

Cit gives low power output

Dit is expensive

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In a phase-shift oscillator, _____ RC sections are generally used.

A3

B4

C2

D5

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In a phase shift oscillator, what are the frequency determining elements?

AL and C

BR, L and C

CR and C

DR and L

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