Q. Signal to noise ratio of microphone is defined as the ratio of output when the sound pressure is __________ to the output in the absence of any sound signal.

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Q. Fields are said to be circularly polarised if their magnitudes are

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Q. Three analog signals, having bandwidths 1200 Hz, 600 Hz, 600 Hz are sampled at their Nyquist rates, encoded with 12 bit words, and time division multiplexed. The bit rate for the multiplexed signal is

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Q. In a CD player the speed of CD is

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Q. In the output of a DM speech encoder, the consecutive pulses are of opposite polarity during time interval t1 < t < t2. This indicates that during this interval

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Q. A fascimile reproduction has a specification of 200 lines per frame, progressive scanning and 5 frames per second. The time to scan one line is

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Q. Sound waves are electromagnetic waves.

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Q. In major diatonic musical scale, an octave is divided into

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Q. The bandwidth of DSB suppressed carrier modulation system when the modulating frequency varies between 500 Hz and 5 kHz is

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Q. The filter circuit for feeding a wooffer has

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Q. In an FM system, when the AF is 500 Hz and the AF voltage is 2.4 V, the deviation is 4.8 kHz. If the AF voltage is now increased to 7.2 V, the new deviation will be

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Q. Modulation is also called detection.

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Q. The maximum range of a transmitter depends on

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Q. Consider the following statements about Yagi Uda antenna

1. It is unidirectional
2. Its gain is about 7 dB
3. It is used at VLF
4. The optimum separation is 0.11

Which of the above are correct?

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Q. In a two stage cascade amplifier, each stage has a gain of 10 dB and noise figure of 10 dB. The overall noise factor is

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Q. An AM signal and a narrowband FM signal with identical carriers, modulating signals and modulation index of 0.1 are added together. The resultant signal can be closely approximated by

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Q. The equation v(t) = A cos [ωct + φ(t)] where A and ωc are constant and φ(t) is a function of base signal represents

1. Phase modulation
2. Amplitude modulation
3. Angle modulation
4. Frequency modulation

Which of the above are true?

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Q. An FM signal with deviation δ is passed through mixer. Its frequency is reduced five fold. The deviation in output of mixer is

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Q. The total number of channels allotted for cellular telephone is

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Q. It is found that in a telephone system 60 subscribers initiate calls during a 30 minute interval and the total duration of all the calls is 100 minutes. The load is

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