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

Match List – I with List – II . List – I List – II (a) 10 km height over earth's surface (i) Thermosphere (b) 70 km height over earth's surface (ii) Mesosphere (c) 180 km height over earth's surface (iii) Stratosphere (d) 270 km height over earth's surface (iv) Troposphere

( a )-( iv ), ( b )-( iii ), ( c )-( ii ), ( d )-( i )

( a )-( i ), ( b )-( iv ), ( c )-( iii ), ( d )-( ii )

( a )-( iii ), ( b )-( ii ), ( c )-( i ), ( d )-( iv )

( a )-( ii ), ( b )-( i ), ( c )-( iv ), ( d )-( iii )

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Which atmosphere layer contains ions and helps in wireless communication?

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Important Questions on Space Communication

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Physics>Modern Physics>Space Communication>Space Communication

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

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Physics>Modern Physics>Space Communication>Space Communication

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>Modern Physics>Space Communication>Space Communication

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

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Physics>Modern Physics>Space Communication>Space Communication

Match List

- I

with List

- II .

	List $- I$		List $- II$
(a)	$10 km$ height over earth's surface	(i)	Thermosphere
(b)	$70 km$ height over earth's surface	(ii)	Mesosphere
(c)	$180 km$ height over earth's surface	(iii)	Stratosphere
(d)	$270 km$ height over earth's surface	(iv)	Troposphere

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Physics>Modern Physics>Space Communication>Space Communication

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>Modern Physics>Space Communication>Space Communication

The waves used for line of sight communication are

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Physics>Modern Physics>Space Communication>Space Communication

For television broadcasting the frequency employed is normally in range,

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Physics>Modern Physics>Space Communication>Space Communication

Which type of communication is employed in mobile phones?

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Physics>Modern Physics>Space Communication>Space Communication

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>Modern Physics>Space Communication>Space Communication

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