Daily Practice Quiz 2: Analog Communication for ESE & GATE EC Exams

Question 1

Direction: A message signal is shown below.

If m(t) is frequency modulated on a carrier with frequency 10⁶ Hz with a frequency deviation constant k_f equal to 0.5 MHz/V, the maximum instantaneous frequency of the modulated signal is

Question 2

Direction: A message signal is shown below.

If m(t) is phase modulated with phase-deviation constant k_p =3 rad/V, the maximum instantaneous frequency is

Question 3

Direction: A narrowband FM signal has a carrier frequency of 100 kHz and a deviation ratio of 0.1. The modulation bandwidth is 500 Hz. This signal is used to generate a wideband FM signal with a deviation ratio of 5 and a carrier frequency of 85 MHz. The scheme utilized to accomplish this is shown in figure.

The required value of frequency multiplication is

Question 4

Direction: A narrowband FM signal has a carrier frequency of 100 kHz and a deviation ratio of 0.1. The modulation bandwidth is 500 Hz. This signal is used to generate a wideband FM signal with a deviation ratio of 5 and a carrier frequency of 85 MHz. The scheme utilized to accomplish this is shown in figure.

The two possible local oscillator frequencies are

Question 5

Direction: A narrowband FM signal has a carrier frequency of 100 kHz and a deviation ratio of 0.1. The modulation bandwidth is 500 Hz. This signal is used to generate a wideband FM signal with a deviation ratio of 5 and a carrier frequency of 85 MHz. The scheme utilized to accomplish this is shown in figure.

The bandwidth of BPF (band pass filter) would be

Question 6

A frequency modulator has a modulator gain of 10Hz/V, and modulating waveform is

For the FM wave, the plot of instantaneous frequency deviation with respect to time t is