Communication systems practice · Mixed difficulty

Intelsat satellite is used for

A TV tower has a height of $100 \mathrm{~m}$. The average population density around the tower is 1000 per $\mathrm{km}^2$. The radius of the earth is $6.4 \times 10^6 \mathrm{~m}$. The population covered by the tower is

Given, below are two statements
Statement I A speech signal of $2\mathrm{ }kHz$ is used to modulate a carrier signal of $1MHz.$ The bandwidth requirement for the signal is $4\mathrm{ }kHz$.
Statement II The side band frequencies are $1002\mathrm{ }kHz$ and $998\mathrm{ k}Hz$. In the light of the above statements, choose the correct answer from the options given below

The relation between the maximum electron density ${N_{\mathrm{max}}}$ and the critical frequency ${f_c}$ for the ionosphere can be given as

The amplitude of $15 \sin (1000 \pi t)$ is modulated by $10 \sin (4 \pi \mathrm{t})$ 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

What is ozone hole

The galaxy in which we live is

The area of television telecast is made twice, the height of antenna will be changed as

An amplitude modulated voltage is expressed as
$e = 10\left( {1 + 0.8\,\cos \,2000\,\pi t} \right)\cos \,3 \times {10^6}\,\pi t\,{\text{volt}}$. The peak
voltage of carrier wave is

The source of time varying magnetic field may be
(A) a permanent magnet
(B) an electric field changing linearly with time
(C) direct current
(D) a decelerating charge particle
(E) an antenna fed with a digital signal
Choose the correct answer from the options given below.

A laser beam is used for carrying out surgery because it

Which of the following is not the main characteristic of laser beam?

Array gain of an antenna is

The maximum range, ${\mathrm{d}_{\mathrm{max}}}$ of radar is

Frequency range for microwaves is

In an FM system a 7 kHz signal modulate 108 MHz carrier so that frequency deviation is 50 kHz. The carrier swing is

In frequency modulation

A ground receiver station is receiving a signal at $100 \mathrm{~MHz}$, transmitted from a ground transmitter at a height of $300 \mathrm{~m}$ located at a distance of $100 \mathrm{~km}$. Then, $\left(N_{\max}=10^{12}\right.$ per $\left.\mathrm{m}^3\right)$

In the above question, if oscillator output is modulated by audio frequencies upto 10 kHz, the frequency range occupied by the side bonds will be

Which one of the following is a full duplex transmission system?

Remote sensing technique is used for

Given, below are two statements
Statement I A speech signal of $2\mathrm{ }kHz$ is used to modulate a carrier signal of $1MHz.$ The bandwidth requirement for the signal is $4\mathrm{ }kHz$.
Statement II The side band frequencies are $1002\mathrm{ }kHz$ and $998\mathrm{ k}Hz$. In the light of the above statements, choose the correct answer from the options given below

In amplitude modulation, the bandwidth is

Large band width for higher data rate is achieved by using

When ${\omega _m}$ is the modulation frequency in frequency modulation, the modulation index is proportional to

Assertion : In the transmission of long distance radio signals. short wave band issued.

Reason : In the shorter wavelength attenuation is very less.

A Television tower has a height of $75 \mathrm{~m}$. What is the maximum distance and area up to which this TV transmission can be received? Take radius of the earth as $6.4 \times$ $10^6 \mathrm{~m}$.

The physical sizes of the transmitter and receiver antenna in a communication system are

The ozone layer absorbs

The population inversion necessary for laser action used in solid state lasers is