Communication Systems

The amplitude of \(15\sin (1000\pi t)\) is modulated by \(10\sin (4\pi t)\) signal. The amplitude modulated signal contains frequency(ies) of
A. \(500\mathrm{Hz}\)
B. \(2\mathrm{Hz}\)
C. \(250\mathrm{Hz}\)
D. \(498\mathrm{Hz}\)
E. \(502\mathrm{Hz}\)

Choose the correct answer from the options given below:

[JEE Main 2023, 31 Jan (Shift 1)]

A sinusoidal carrier voltage is amplitude modulated. The resultant amplitude modulated wave has maximum and minimum amplitude of 120 V and 80 V respectively. The amplitude of each sideband is:

[JEE Main 2023, 30 Jan (Shift 1)]

A TV transmitting antenna is \(98\mathrm{m}\) high and the receiving antenna is at the ground level. If the radius of the earth is \(6400\mathrm{km}\), the surface area covered by the transmitting antenna is approximately:

[JEE Main 2023, 8 Apr (Shift 1)]

An antenna is mounted on a \(400\mathrm{m}\) tall building. What will be the wavelength of signal that can be radiated effectively by the transmission tower upto a range of \(44\mathrm{km}\) ?

[JEE Main 2021, 27 Aug (Shift 2)]

The power radiated from a linear antenna of length \(l\) is proportional to
(Given,\(\lambda =\) Wavelength of wave):

[JEE Main 2023, 8 Apr (Shift 2)]

If a message signal of frequency ' \({f}_{m}\) ' is amplitude modulated with a carrier signal of frequency ' \({f}_{c}\) ' and radiated through an antenna, the wavelength of the corresponding signal in air is:

[JEE Main 2021, 25 Feb (Shift 2)]

A message signal of frequency 5 kHz is used to modulate a carrier signal of frequency 2 MHz. The bandwidth for amplitude modulation is:

[JEE Main 2023, 25 Jan (Shift 1)]

What should be the height of transmitting antenna and the population covered if the television telecast is to cover a radius of \( 150 \mathrm{~km} \)? The average population density around the tower is \( 2000 / \mathrm{km}^{2} \) and the value of \( R_{e}=6.5 \times 10^{6} \mathrm{~m} \).

[JEE Main 2021, 22 Jul (Shift 2)]