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Communication Systems
practice.

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Q141

Open question

A Frequency Hopping Spread Spectrum system has its frequency synthesizers controlled by five stage shift-registers with feedback connections taken from the second and fifth stages. The number of slots available for frequency hopping is

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Q142

Open question

Consider a WSS random process X(t), whose amplitudes are normally distributed with E(x(t)) = 0 and R_x(τ) = e^-2[τ]. Then P(X(t)) ≤ 2) = ?

Q (α) = \frac{1}{2 π} α \int \infty e^{- \frac{x ^{2}}{2}} d x

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Q143

Open question

If f_c is the carrier wave frequency and f_m is the modulation frequency, then in the resulting amplitude modulated waveform the upperside band consists of:

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Q144

Open question

For identical total transmitted power, the ratio of S/N for wide band FM to S/N of DSB-AM (with m_a = 1) is:
(Given f_m = 15 KHz & frequency deviation = ±75 KHz)

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Q145

Open question

The surface wave eventually disappears as one moves away from the transmitter because of

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Q146

Open question

Which of the following is not true?

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Q147

Open question

The amount of frequency deviation in FM signal depends on

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Q148

Open question

The primary colour used in colour television is-

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Q149

Open question

A 1 mW video signal having a bandwidth of 100 MHz is transmitted to a receiver through a cable that has 40 dB loss. If the effective one-sided noise spectral density at the receiver is 10^-20 Watt/Hz, then the signal-to-noise ratio at the receiver is

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Q150

Open question

Which of the following is not a digital-to-analog conversion?

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Q151

Open question

Consider the frequency modulated signal 10cos[2π × 10^t + 5sin(2π + 1500t) + 7.5sin(2π × 1000t)] with carrier frequency of 10⁵ Hz. The modulation index is

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Q152

Open question

For a frequency-modulated signal, the modulation index is doubled. The average power of the modulated signal is

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Q153

Open question

Let U and V be two independent zero mean Gaussian random variables of variances

\frac{1}{4}

and

\frac{1}{9}

respectively. The probability P(3V ≥ 2U) is

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Q154

Open question

For an angle modulated signal, x(t) = 6cos[2π × 10⁶ t + 2sin(8000πt) + 4cos(8000πt)]V.
The average power of x(t) is

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Q155

Open question

A random process is called ergodic process if-

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Q156

Open question

In case of double side band side AM, power contained in upper side band is

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Q157

Open question

What is the total power carried by sidebands of the AM wave (DSB) for tone modulation for µ = 0.4?

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Q158

Open question

Mean of two batsmen A and B are

X_{A} = 48

and

X_{B} = 46.

Their coefficient of variation are 0.37 and 0.26 respectively. Then which of the following is correct?

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Q159

Open question

A signal with two frequency components at 6 kHz and 12 kHz, is sampled at the rate of 16 kHz and then passed through a Low Pass filter having a cut-off frequency of 16 kHz. The output signal of the filter

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Q160

Open question

Light is good for telecommunications because it is:

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Communication Systemspractice.

Communication Systems
practice.