Q. Which of the following sampling frequencies is considered adequate in voice telephony?

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Q. In telephone systems the relation between load ρ, number of calls initiated during a specified interval λ and average duration of a call (h) is

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Q. In a Vidicon camera tube

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Q. In a CD the sampling frequency is nearly

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Q. Consider the following statements about loop antenna

1. It is suitable for direction finding application
2. It is a single turn or multiturn coil carrying RF current
3. The loop is surrounded by a magnetic field everywhere perpendicular to the loop

Which of the above statements are correct?

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Q. Which of the following is present in both TRF receiver and superheterodyne receiver?

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Q. Which camera tube has highest dark current?

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Q. If a sound wave has a frequency of 50 Hz, the wavelength is

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Q. Skin depth at 1000 MHz in comparison with that at 500 MHz is

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Q. Consider the following

1. Generation of SSB signals
2. Design of minimum phase type filters
3. Representation of band pass signals

Which of the above applications is Hilbert transform used?

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Q. The dc voltage on plate modulated class C amplifier is 8 kV. If the peak modulating voltage is 4 kV, the peak RF voltage delivered to load is

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Q. The minimum step size required for a Delta modulator operating at 36 samples/sec to track the signal (here u(t) is the unit step function) x(t) = 125t (u(t) - u(t - 1)) + (250 - 125t) (u(t - 1) - u(t - 2)) So that slope overload is avoided, would be

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Q. An FM signal with a deviation δ is passed through a mixer, and has its frequency reduced 5 fold. The deviation in the output of the mixer is

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Q. In PCM, if the number of quantization levels is increased from 4 to 64, then the bandwidth requirement will approximately be increased __________ times.

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Q. A tweeter should be fed from the input through a

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Q. The modulation index is, if fm = 500 Hz, Δf = 2.25 kHz

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Q. Which of the following is true in a tape recorder?

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Q. In a high speed modem the data rate handled is about

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Q. Trinitron is a monochrome picture tube.

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Q. The first pulse in a TV remote control is

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