Q. In an AM wave the carrier and one of the side bands is suppressed. If m = 1, the percentage saving in power is

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Q. Assertion (A): An electronic tuner uses varactor diode

Reason (R): The capacitance of a varactor diode depends on the magnitude of reverse bias.

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Q. A superheterodyne receiver is to operate in the frequency range 550 kHz - 1650 kHz, with the intermediate frequency of 450 kHz. Let R = Cmin/Cmax denote the required capacitance ratio of the local oscillator and I denote the image frequency (in kHz) of the incoming signal. If the receiver is tuned to 700 kHz, then

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Q. In a tape recorder the output from RF oscillator is given to

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Q. A + 1.9 lens has a focal length of 25 mm. The diameter of lens is about

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Q. Which of the following terms are applicable to troposcatter propagation?

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Q. If the amplitude of the voltage is kept constant, but its frequency is raised to 6 kHz, the new deviation will be for the modulation index is, if fm = 500 Hz, Δf = 2.25

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Q. In TV scanning sequence of lines is

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Q. In equally tampered scale, frequency of each tone equals the frequency of lower adjacent tone multiplied by

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Q. A carrier is modulated by two modulating waves A and B having modulation indices of 0.6 and 0.8 respectively. The overall modulation index is

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Q. A communication channel disturbed by additive white, Gaussian noise has a bandwidth of 4 kHz and SNR of 15. The highest transmission rate that this channel can support (in k bits/sec) is

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Q. Which of the following microphones is used as a standard for calibration?

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Q. The reactance of coupling capacitor for AC signals in an amplifier, should be

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Q. Assertion (A): In India we use CCIR-B standard

Reason (R): Video signals are frequency modulated.

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Q. CATV stands for

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Q. Household tape recorders use

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Q. A 400 W carrier is modulated to a depth of 75 percent. The total power in modulated wave will be

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Q. A geostationary satellite

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Q. For an ideal 3000 Hz channel, Nyquist rate is

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Q. 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.

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