Q. A carrier is simultaneously modulated by two sine waves having modulation indices of 0.4 and 0.3. The total modulation index will be

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Q. A 1000 kHz carrier is simultaneously modulated with 300 Hz, 800 Hz and 2 kHz audio sine waves. Which of the following frequency is least likely to be present in the output?

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Q. A 400 W carrier is amplitude modulated with m = 0.75. The total power in AM is

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Q. c(t) and m(t) are used to generate an FM signal. If the peak frequency deviation of the generated FM signal is three times the transmission bandwidth of the AM signal, then the coefficient of the term cos [2π(1008 x 10³t)] in the FM signal (in terms of the Bessel Coefficients) is

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Q. Non-coherently detection is not possible for

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Q. Tracking of extra terrestrial objects requires

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Q. Assertion (A): Free space does not interfere with normal radiation and propagation of radio waves

Reason (R): Free space has no magnetic or gravitational fields.

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Q. Which of the following is taken as reference antenna for directive gain?

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Q. Push pull amplifier is

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Q. When the channel is noisy, producing a conditional probability of error p = 0.5; the channel capacity and entropy function would be, respectively,

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Q. In CCIR-B system, the time between start of one H syn. pulse and next is

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Q. Counterpoise is used in coils having

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Q. In standing wave pattern on a transmission line

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Q. If the bandwidth is increased by 2, the γFM γAM (where γ is the ratio of SNR of output to SNR at input, FM is frequency modulation and AM is amplitude modulation) is increased by a factor of

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Q. A carrier wave carries information.

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Q. Frequency shift keying is used mostly in

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Q. A generator is feeding power to a transmission line of characteristic impedance Z0. The line is terminated in impedance ZL. Standing waves will be set up if

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Q. In sound recording the degree of pre-emphasis is about 6 dB/ octave.

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Q. Space wave may be a direct wave or wave reflected from earth.

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Q. Radio broadcasts are generally

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