ECE :: Communication Systems
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On modulating a carrier of frequency fc by an audio signal fs, the following components has resulted:
fc, fc + fs and fc - fs
What is this type of modulation likely to be? -
Which of the following is not necessarily the advantage of SSB over double sideband, full carrier AM?
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A signal m(t) = 5 cos 2p 100 t frequency modulates a carrier. The resulting FM signal is
10 cos {(2p 105 t) + 15 sin (2p 100 t)}
The approximate bandwidth of the FM would be -
Some possible functions of AGC in a TV receiver are
- To increase gain for weak signals
- To decrease gain for strong signals
- To change the contrast when we switch from one channel to other
- To reduce flutter
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A monostable multivibrator is used to generate PWM because it can
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Consider the following statements in amplitude modulation
- The harmonic and intermodulation distortion may occur in audio and RF amplifiers
- The sum and difference frequencies are present in the output of mixer
- The diode detector has audio frequencies in its output
- A balanced modulator cannot produce an AM with suppressed carrier
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A resistor R is in parallel with capacitance C. The rms noise voltage of resistor in the equivalent circuit can be written as
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Assertion (A): In angle modulation the transmitted amplitude is constant.
Reason (R): Angle modulation has good immunity to noise and interference.
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A 1000 kHz carrier is simultaneously modulated with 300 Hz, 800 Hz and 2 kHz audio sine waves. The frequencies present in the output will be
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