Amplifier Fundamentals MCQs

Practice Amplifier Fundamentals MCQs with four options, answers and explanations for focused Electronics & Telecommunication Engineering revision.

Question 1

Electronic Devices & CircuitsAmplifier Fundamentals

A voltage amplifier produces 2 V output for a 20 mV input. Its voltage gain magnitude is?

A10
B20
C100
D1000

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Correct Answer: C. 100

Explanation: Voltage gain magnitude = 2 V / 0.020 V = 100.

Reference: Standard analog electronics: voltage gain

Question 2

Electronic Devices & CircuitsAmplifier Fundamentals

A voltage gain of 100 corresponds to approximately how many decibels?

A20 dB
B40 dB
C60 dB
D100 dB

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Correct Answer: B. 40 dB

Explanation: Voltage gain in dB is 20 log10(Av). For Av = 100, 20 log10(100) = 40 dB.

Reference: Standard electronics: decibel voltage gain

Question 3

Analog ElectronicsAmplifier Fundamentals

An amplifier produces 5 V output for a 50 mV input. Its voltage gain magnitude is?

A10
B50
C100
D500

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Correct Answer: C. 100

Explanation: Voltage gain is 5/0.05 = 100.

Reference: Standard analog electronics: amplifier fundamentals

Question 4

Analog ElectronicsAmplifier Fundamentals

A voltage gain magnitude of 10 is approximately equal to?

A10 dB
B20 dB
C40 dB
D100 dB

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Correct Answer: B. 20 dB

Explanation: Voltage gain in dB is 20 log10(10) = 20 dB.

Reference: Standard analog electronics: amplifier fundamentals

Question 5

Analog ElectronicsAmplifier Fundamentals

A gain reduction of 3 dB in voltage magnitude corresponds approximately to multiplication by?

A0.1
B0.5
C0.707
D0.9

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Correct Answer: C. 0.707

Explanation: 20 log10(0.707) is approximately -3.01 dB.

Reference: Standard analog electronics: amplifier fundamentals

Question 6

Analog ElectronicsAmplifier Fundamentals

For cascaded amplifier stages having voltage gains of 20 dB and 30 dB, the total voltage gain in decibels is?

A10 dB
B25 dB
C50 dB
D600 dB

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Correct Answer: C. 50 dB

Explanation: Cascaded gains multiply in linear units, so their decibel gains add: 20 + 30 = 50 dB.

Reference: Standard analog electronics: amplifier fundamentals

Question 7

Analog ElectronicsAmplifier Fundamentals

A voltage amplifier intended to drive a low-resistance load with good voltage transfer should generally have?

ALow output resistance
BHigh output resistance
CZero input resistance
DNo power supply

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Correct Answer: A. Low output resistance

Explanation: Low output resistance minimizes voltage drop inside the amplifier when load current flows and improves voltage delivery to the load.

Reference: Standard analog electronics: amplifier output resistance

Question 8

Analog ElectronicsAmplifier Fundamentals

For maximum power transfer from a source represented by a Thevenin resistance Rs to a purely resistive load, the load resistance should ideally be?

ARs/2
BRs
C2Rs
DInfinite

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Correct Answer: B. Rs

Explanation: For a purely resistive Thevenin source, maximum load power occurs when RL=Rs.

Reference: Standard analog electronics: impedance matching

Question 9

Analog ElectronicsAmplifier Fundamentals

A voltage amplifier intended to avoid loading a high-resistance signal source should ideally have?

AHigh input resistance
BVery low input resistance
CZero voltage gain
DInfinite output resistance only

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Correct Answer: A. High input resistance

Explanation: High input resistance draws little current from the source, minimizing loading and preserving the source voltage.

Reference: Standard analog electronics: amplifier input resistance