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What is the relationship between velocity of light and refractive index?

Important Questions on Space Communication

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The earth's atmosphere is divided into different layers. Out of these layers, ionosphere consists of
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The physical sizes of the transmitter and receiver antenna in a communication system are:
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For television broadcasting the frequency employed is normally in range,
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The waves used for line of sight communication are
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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:
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The waves suitable for transmission of radio signals are
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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 B0 is an appropriate constant):
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An EM wave is propagating in a medium with a velocity V=V 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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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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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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Which type of communication is employed in mobile phones?
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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 =6.4×106 m).
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Match ListI with ListII.
  ListI   ListII
(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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The frequency suitable for beyond-the-horizon communication using sky waves is
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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 =6.4×106 m)
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In a communication system operating at wavelength 800 nm, only one percent of source frequency is available as signal bandwidth. The number of channels accommodated for transmitting TV signals of band width 6 MHz are (Take velocity of light c=3×108 m/s, h=6.6×10-34 J-s )
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To double the covering range of a TV transmitting tower, its height should be multiplied by:
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The ionospheric layer acts as a reflector for the frequency range:
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Construction of pulse radar is much simpler than a Doppler radar.