Tag: satellites in communication

Questions Related to satellites in communication

Match List-1 with List-2. 

List-1 List-2
a. Point to point communication e. RADAR
b. broadcast communication f. AM radio
c. Line of sight g. FM radio communication
d. Satellite communication h. Traditional telephony
i. Mobile telephony
j. TV
evs - i communication and mass media understanding communication and impact of mass media satellites in communication importance of transport system artificial satellite

  1. a-h; b-f,g,j; c-e; d-i,j

  2. a-e; b-i,j; c-h; d-g,f

  3. a-f ; b-h,i,j; c-g; d-e

  4. a-g; b-f,g,j; c-e; d-i,j

Show answer
Correct Option: A
Explanation:
(a-h): A point-to-point connection refers to a communications connection between two nodes or endpoints.
(b-f, g ,j): Reaches a wider range at faster speed.
(c-e) Line of sight is a type of propagation that can transmit and receive data only where transmit and receive stations are in view of each other without any sort of an obstacle between them.
(d-i, j) Signal transferring between the sender and receiver is done with the help of satellite.

The frequency of transmission of a ratio station is $30\, MHz$. The wavelength of the waves transmitted by the centre will be- 

evs - i communication and mass media understanding communication and impact of mass media satellites in communication importance of transport system artificial satellite

  1. $5$ meter

  2. $10$ meter

  3. $15$ meter

  4. $20$ meter

Show answer
Correct Option: B

Long range transmission of TV-signal is done by

evs - i communication and mass media understanding communication and impact of mass media satellites in communication importance of transport system artificial satellite

  1. space wave

  2. sky wave

  3. ground wave

  4. artificial satellite

Show answer
Correct Option: D
Explanation:

TV-signal ( $30: MHz$ - $300:MHz$) are not reflected by ionosphere. Therefore, sky-wave propagation is not possible and similarly ground and space wave is also not feasible. Hence, they are transmitted to artificial satellite from where they are transmitted back to the Earth.

What fraction of the surface area of earth can be covered to establish communication by one geostationary satellite?

evs - i communication and mass media understanding communication and impact of mass media satellites in communication importance of transport system artificial satellite

  1. $\displaystyle\frac{1}{2}$

  2. $\displaystyle\frac{1}{3}$

  3. $\displaystyle\frac{1}{4}$

  4. $\displaystyle\frac{1}{8}$

Show answer
Correct Option: B
Explanation:

We uses three geostationary satellites placed at the vertices of an equilateral triangle, then the entire earth can be covered by the communication network, each satellite covers $1/3$ of the globe.

A ground receiver station is receiving a signal at (a) 5 MHz and (b) 100MHz, transmitted from a ground transmitter at a height of 400m located at a distance of 125km. Identify whether it is coming via space wave or sky wave propagation or satellite transponder. Radius of earth = $6.4\times { 10 }^{ 6 }m$; maximum number density of electrons in ionosphere = ${ 10 }^{ 12 }{ m }^{ -3 }$ 


evs - i communication and mass media understanding communication and impact of mass media satellites in communication importance of transport system artificial satellite

  1. $9MHz$

  2. $5MHz$

  3. $4MHz$

  4. All of these.

Show answer
Correct Option: A
Explanation:
Height of the ground transmitter $=30\ cm$
Range of transmission $=100\ km$
maximum distance covered by space wave propagation is
$d=\sqrt{2\ Rh}$
$=\sqrt{2\times 64\times 10^{6}\times 300}$
$=62\ km$
critical frequency for ionospheric propagation is, 
$F _{C}=9(N _{max})^{112}$
$=9(10^{12})^{112}$
$=9\times 10^{6}=9\ MHZ$

For satellite communication which wave is used?

physics artificial satellite communication and mass media understanding communication and impact of mass media satellites in communication

  1. Space wave

  2. Sky wave

  3. Ground wave

  4. Microwave

Show answer
Correct Option: A
Explanation:

A space wave travels in a straight line from transmitting antenna to the receiving antenna. Space waves are used for line of sight communication as well as satellite communication.

State whether the given statement is True or False :

Remote sensing is a technique of collection of information about an object, without a physical contact.

physics artificial satellite communication and mass media understanding communication and impact of mass media satellites in communication

  1. True

  2. False

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Correct Option: A
Explanation:

Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus it is in contrast to on site observation. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth.
Hence, the statement is true.

As the height of a satellite orbit gets lower, the speed of the satellite _________.

physics artificial satellite communication and mass media understanding communication and impact of mass media satellites in communication

  1. decreases

  2. increases

  3. remains the same

  4. none of the above

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Correct Option: B
Explanation:

$V=\sqrt { \cfrac { GMe }{ r }  } \ \therefore V\propto \cfrac { 1 }{ \sqrt { r }  } $

With decrease in $'r'$, velocity of satellite $increases$.

Let $R _s$ and $R _m$ be the distance of the geostationary satellite and moon from the center of earth. Then $\dfrac{R _m}{R _s}$ is

physics artificial satellite communication and mass media understanding communication and impact of mass media satellites in communication

  1. $(29)^{1/2}$

  2. $(29)^{2/3}$

  3. $29$

  4. $(29)^{3/2}$

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Correct Option: B

If the satellite is stopped sudden;y in its orbit which is at a distance radius of earth from earth's surface and allowed to fall freely into the earth. the speed with which it hits the surface of earth will be:

physics artificial satellite communication and mass media understanding communication and impact of mass media satellites in communication

  1. $38,525 km/s$

  2. $1,525 km/s$

  3. $18,525 km/s$

  4. $28,525 km/s$

Show answer
Correct Option: D