Noise Figure MCQs

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

Question 1

Communication SystemsNoise Figure

A receiver has noise figure F=2 as a linear ratio. Its noise figure in decibels is approximately?

A1 dB
B3.01 dB
C6.02 dB
D20 dB

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Correct Answer: B. 3.01 dB

Explanation: NF(dB)=10log10(F)=10log10(2)≈3.01 dB.

Reference: Standard communication systems: noise figure

Question 2

Communication SystemsNoise Figure

The noise factor of an ideal noiseless receiver is?

A0
B1
C2
DInfinite

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Correct Answer: B. 1

Explanation: Noise factor F=SNRin/SNRout. An ideal noiseless system does not degrade SNR, so F=1, corresponding to 0 dB noise figure.

Reference: Standard communication systems: noise figure

Question 3

Communication SystemsNoise Figure

In a cascade of receiver stages, the overall noise performance is especially sensitive to the noise characteristics of the?

AFirst stage
BLast stage only
CPower supply only
DAntenna cable length only regardless of loss

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Correct Answer: A. First stage

Explanation: Friis' formula shows that noise added by early stages is most important because later-stage noise contributions are divided by preceding gain.

Reference: Standard communication systems: noise figure