COMMUNICATION SYSTEMS QUIZ

An FM radio receiver which is tuned to a 91.6 MHz broadcast station may receive an image frequency of __________ MHz.

80.9

70.2

113

102.3

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A cordless telephone using separate frequencies for transmission in base and portable units is known as

Duplex arrangement

Half duplex arrangement

Either A or B

Neither A nor B

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The modulation index of an FM is changed from 0 to 1. How does the transmitted power change?

Gets halved

Gets increased by 50 percent

Remains unchanged

Gets doubled

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An audio signal (say from 50 Hz to 10000 Hz) is frequency translated by a carrier having a frequency of 106 Hz. The values of initial (without frequency translation) and final (after frequency translation) fractional change in frequency from one band edge to the other are

200 and 10.01

200 and 200

200 and 100.1

200 and 1.01

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To eliminate ghosts in the picture

Use a longer transmission line

Change the antenna orientation of location

Connect a booster

Twist the transmission line

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SSB can be generated by

Good attenuation characteristics

All of these

Phase cancellation method

Filter method

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Which of the following does not cause losses in optical fibre cables?

Impurities

Attenuation in glass

Microbending

Stepped index operation

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What is the purpose of peak clipper circuits in radio transmitters?

To prevent overmodulation

To reduce bandwidth

To regulate oscillator I/P voltage

To increase bandwidth

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The characteristic impedance of a twin wire feeder used for TV signals is about

300 ohm

100 ohm

1000 ohm

500 ohm

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Which of the following is a digital modulation technique?

PSK

All

DM

PCM

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