Communication Systems - ECE Questions and Answers

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The contrast control in colour TV receiver is done by

chroma amplifier

SAW filter

video detector

luminance amplifier

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The requirements of carrier frequency are

precise frequency value

low frequency drift

both (a) and (b)

neither (a) nor (b)

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If N bits are lumped together to get an N-bit symbol, the possible number of symbols is

2^N

2^{N - 1}

2^{N - 2}

2^{N - 4}

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The received signal frequency at any time of a super-heterodyne receiver having IF = 456 kHz is 1 MHz. The corresponding image signal is

within the medium band

outside the medium band

depend upon modulation index

depends on Modulating frequency

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For an ideal 3000 Hz channel, Nyquist rate is

3000 bps

6000 bps

9000 bps

12000 bps

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Assertion (A): Electromagnetic waves in free space spread uniformly in all directions from a point source

Reason (R): Free space has no interference or obstacles.

Both A and R are correct and R is correct explanation of A

Both A and R are correct but R is not correct explanation of A

A is correct but R is wrong

A is wrong but R is correct

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In the FM wave described by equation v = 15 sin (4 x 10⁸ t + 3 sin 1100 t), the maximum frequency deviation is

175 Hz

525 Hz

3 Hz

58.33 Hz

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The radar cross-section of a target depends an

frequency

polarization of incident wave

aspect of target

all of the above

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The Nyquist sampling interval, for the signal sin c (700t) + sin c (5000 t) is