Test: Analog Communication - 2 - Electronics and Communication Engineering (ECE) MCQ

Three message signals each band limited to 10 kHz, 10 kHz, and 5 KHz are transmitted through a channel using frequency division multiplexing. The modulation techniques used are any, D513-SC, SSB respectively. The guard band is 2 KHz. Band width of the channel is

A signal '4 t is band limited to the frequency range 0 to f_n. The signal frequency is translated by multiplying it by the signal V, t —cos2πf_ct . The value of f_c such that the bandwidth of the translated signal is 1% of the carrier frequency f_c will be

The peak amplitude of an AM signal for tone modulation with carrier having maximum amplitude as 5 V, varies from 2 to 8 V then the sideband power is  _________________________ (W)

Consider a frequency multiplier shown in the figure below.ss

A NBFM signalX Mal t with f, = 200KHz and f, ranges 50 Hz to 150 KHz is given as an input to frequency multiplier. The Maximum Frequency deviation of the NBFM is 25 Hz. The maximum frequency deviation at the output is 75 KHz.

Q. The required frequency multiplication n is

Consider a frequency multiplier shown in the figure below.ss

A NBFM signalX Mal t with f, = 200KHz and f, ranges 50 Hz to 150 KHz is given as an input to frequency multiplier. The Maximum Frequency deviation of the NBFM is 25 Hz. The maximum frequency deviation at the output is 75 KHz.

Q. The carrier frequency at the output is

SSB modulation may be viewed as a hybrid form of amplitude modulation and frequency modulation. Assuming a message signal m(t) = sin t and a carrier frequency 'f_c', the instantaneous frequency for the lower side band is

Given 

In a certain experimental conducted with f_m = 1 kHz and increasing A_m(starting from 0 volts), it is found that the carrier component of the FM signal is reduced to zero for the first time when A_m = 2 volts.

The frequency sensitivity of the modulator is

If E_x and E_y represent the energies of m(t) and y(t) respectively, then _______________

Determine the spectrum of y(t) in the system shown below.

Consider the scheme shown

If x (t) = m (t) cos (co_ct) then y (t) is

The above schematic generates FM signal as a wideband frequency modulator

using the indirect method. The output FM signal is characterized by f_c = 100 MHz, Δf = 75kHz (min). If the phase modulator has a modulation index of β= 0.3 radians, then n₁, n₂ are respectively

What is the standard IF frequency for AM receivers?

 Consider a message signal m(t) = 2sin(10007t)

Phase sensitivity constant Kp=5rad/V

Frequency sensitivity constant K_f=75KHz/V

Q. If amplitude of message signal is doubled, then bandwidth for FM and PM will be

A 20 KW and 1 MHz carrier is frequency modulated by a sinusoidal signal so that the maximum frequency deviation is 50 KHz and the message signal is band limited to 500 KHz. The generated FM signal is amplitude modulated using carrier of 1 GHz.

Q. The bandwidth of the generated signal is

A 20 KW and 1 MHz carrier is frequency modulated by a sinusoidal signal so that the maximum frequency deviation is 50 KHz and the message signal is band limited to 500 KHz. The generated FM signal is amplitude modulated using carrier of 1 GHz.

Q. The bandwidth of the generated AM signal is

​The input x(t) and the output y(t) of a certain nonlinear channel are related as y(t) = x(t) + 0.001 x²(t)

If frequency spectrum of input signal is

Q. The bandwidth of the output signal is

​The input x(t) and the output y(t) of a certain nonlinear channel are related as y(t) = x(t) + 0.001 x²(t)

If frequency spectrum of input signal is

Q. Spectrum of the received signal after appropriate low pass filtering is