A plane electromagnetic wave is propagating along the direction i ^ + j ^ 2 , with its polarization along the direction k . ^ The correct form of the magnetic field of the wave would be (here B 0 is an appropriate constant):

B 0 i ^ - j ^ 2 c o s ω t - k i ^ + j ^ 2

B 0 j ^ - i ^ 2 c o s ω t + k i ^ + j ^ 2

B 0 k ^ c o s ω t - k i ^ + j ^ 2

B 0 i ^ + j ^ 2 c o s ω t - k i ^ + j ^ 2

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Explain ground wave propagation.

Important Questions on Communication System

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

The frequency suitable for beyond-the-horizon communication using sky waves is

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

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

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

For television broadcasting the frequency employed is normally in range,

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

High frequency waves follow:

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

A TV transmission tower has a height of

140 m

and the height of the receiving antenna is

40 m .

What is the maximum distance upto which signals can be broadcasted from this tower in LOS (Line of Sight) mode? (Given: radius of earth

= 6.4 \times 10^{6} m) .

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

Which type of communication is employed in mobile phones?

MEDIUM

Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

A plane electromagnetic wave is propagating along the direction

\frac{\hat{i} + \hat{j}}{\sqrt{2}},

with its polarization along the direction

\hat{k .}

The correct form of the magnetic field of the wave would be (here

B_{0}

is an appropriate constant):

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

The earth's atmosphere is divided into different layers. Out of these layers, ionosphere consists of

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

To double the covering range of a TV transmitting tower, its height should be multiplied by:

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

Long-range radio transmission is possible when the radio waves are reflected from the ionosphere. For this to happen the frequency of the radio waves must be in the range:

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

An EM wave is propagating in a medium with a velocity

\vec{V} = V \hat{i}

. The instantaneous oscillating electric field of this em wave is along

+ y

axis. Then the direction of oscillating magnetic field of the EM wave will be along

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

In a communication system operating at wavelength

800 n m,

only one percent of source frequency is available as signal bandwidth. The number of channels accommodated for transmitting

T V

signals of band width

6 M H z

are (Take velocity of light

c = 3 \times 10^{8} m / s, h = 6.6 \times 10^{- 34} J - s

)

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

An antenna uses electromagnetic waves of frequency

5 M H z

. For proper working, the size of the antenna should be

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

For efficient transmission and reception, the height of antenna should be atleast

MEDIUM

Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

The maximum line-of-sight distance undefined between the transmitting antenna of height undefined and receiving antenna of height undefined in undefined communication is undefined radius of the earth)

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

The radius of the Earth is

6400 km

. If the height of an antenna is

500 m

, then its range is

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

100 m

long antenna is mounted on a

500 m

tall building. The complex can become a transmission tower for waves with

λ

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

In a line of sight radio communication, a distance of about

50 km

is kept between the transmitting and receiving antennas. If the height of the receiving antenna is

70 m,

then the minimum height of the transmitting antenna should be: (Radius of the Earth

= 6.4 \times 10^{6} m

)

MEDIUM

Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

A transmitting antenna at the top of a tower has a height $32 m$ and the height of the receiving antenna is $50 m$ . What is the maximum distance between them for satisfactory communication in line of sight (LOS) mode?

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Physics>Electronics>Communication System>Propagation of Electromagnetic Waves

A plane electromagnetic wave of wavelength

λ

has an intensity

I

. It is propagating along the positive

Y -

direction. The allowed expressions for the electric and magnetic fields are given by:

Explain ground wave propagation.

Important Questions on Communication System

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