Q. A signal m(t) with bandwidth 500 Hz is first multiplied by a signal g(t) where g(t) is given by below equation. The resulting signal is then passes through an ideal low pass filter with bandwidth 1 kHz the output of the low pass filter would be

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Q. If a signal voltage Vs is accompanied by a noise voltage Vn the signal to noise ratio is

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Q. A sequence x(n) with the z transform X(z) = z⁴ + z² - 2z + 2 - 3z - 4 is applied as an input to a linear, time invariant system with the impulse response h(n) = 2δ(n - 3) where δ(n) is given below. The output at n = 4 is

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Q. In a satellite transponder the power amplifier feeds power P to the transmitting antenna of gain G. If distance of earth is d, the power flux density is

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Q. In a two stage cascade amplifier the equivalent noise temperatures are Te1 and Te2. If the gains of the two stages are G1 and G2, the overall noise temperature Te is

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Q. A π matching network for coupling the transmitter output of the antenna is shown in figure.
In this C₂ should be tuned for

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Q. In figure (A) and (B)

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Q. For a three stage cascaded amplifier, having gains of G₁, G₂ and G₃ and noise figures of F₁, F₂, F₃ the overall noise figure

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Q. Which of the following could be the equation for non-linear resistor shown in figure?

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Q. Figure shows the arrangement of

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Q. Noise figure is defined as

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Q. If N is the number of binary digits needed to assign individual binary code designations to the M quantization levels, the signal to quantization noise ratio S0/Nq in PCM is

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Q. If Vs is signal voltage, Vn is noise voltage, signal to noise ratio S/N is defined as

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Q. The PDF of a Gaussian random variable X is given by following equation. The probability of the event {X = 4} is

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Q. A single tone modulating signal Vm cos ωt modulates a carrier A cos ωct. The carrier power (modulated) and side band powers are respectively

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Q. Modulation index of a AM wave is measured using oscilloscope. The display on the CRO is as shown in figure it can be concluded that

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Q. If f is frequency and d is distance, path attenuation a between isotropic antennas is given by

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Q. If the transmitted pulse power of a radar is Pt (peak value) and the antenna is isotropic, the power density at a distance r is

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Q. In delta modulation, the output signal to quantization noise ratio S0/Nq is (N is the number of bits)

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Q. If B is channel bandwidth, S is signal power and N is the total noise within the channel bandwidth, the channel capacity C of a white band limited gaussian channel is

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