Q. The open loop gain of an amplifier is 50 but is likely to change by 20%. If negative feedback with β = 0.1 is used, the change in gain will be about

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Q. Audio amplifiers need

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Q. For an ideal 3000 Hz channel, S/N ratio is

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Q. Which of the following types of noise assumes greater importance at high frequencies?

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Q. In transistor radio receivers the number of IF amplifier stages are

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Q. To relay outdoor remotely located live programs, TV transmitter use

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Q. If each short element of signal occupies 20 ms, the speed is

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Q. The Hilbert transform of cos ω₁t + sin ω₂t is

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Q. In ionosphere incidence angle is 60°. The maximum usable frequency fm is equal to

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Q. The generally used value of EHV supply in TV receivers is

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Q. The number of channels available in MF band (300 kHz - 3 MHz) for AM modulating signal of 20 kHz is

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Q. The function of blend control in stereo system is

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Q. The output resistance of a microphone is 20 ohms. It is to feed a line of impedance 320 ohms. To ensure maximum power transfer, the turn ratio of transformer is

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Q. In a reactance FET, gm = 9 x 10‾³ Siemens, gate to source resistance is one-ninth of reactance of gate to drain capacitor and frequency is 4 MHz. The capacitive-reactance is

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Q. Audio cassettes used in household tape recorders have a width of

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Q. The receiver of a pulsed RADAR can detect signal power in the order of

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Q. In a 100% amplitude modulated signal, the power in the upper sideband when carrier power is to be 100 W and modulation system SSBSC, is

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Q. The number of channels in a stereophonic system is

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Q. When the carrier is unmodulated, a certain transmitter radiates 9 kW when the carrier is sinusoidally modulated the transmitter radiates 10.125 kW. The modulation index will be

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Q. A signal x(t) = 100 cos (24π x 10³t) is ideally sampled with a sampling period of 50 μ sec and then passed through an ideal low pass filter with cut off frequency of 15 kHz Which of the following frequencies are present at the filter output?

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