Tag: evs - i

Questions Related to evs - i

 How does communication between satellite be achieved

  1. Using satellite cross-links

  2. Intersatellite links (ISLs)

  3. Through ground stations

  4. Both A and B


Correct Option: D
Explanation:

A crosslink is when satellites communicate directly with eachother, instead of communicating with a ground station which, in turn, communicates with other satellites. Frequencies that are quickly attenutated in the atmosphere are commonly used, making the link undetectable and unjamable from the ground.


ISLs permits a satellite to communicate, when it is not visible from a receiving ground station, using a geostationary TLC satellite.

The downlink frequency in the C-band transponder is about

  1. 6 GHz

  2. 4 GHz

  3. 14 GHz

  4. 11 GHz


Correct Option: B
Explanation:

$Answer:-$ B

$C-Band(4-8GHz)$

Primarily used for satellite communications, for full-time satellite TV networks or raw satellite feeds. Commonly used in areas that are subject to tropical rainfall, since it is less susceptible to rainfade than Ku band (the original Telstar satellite had a transponder operating in this band, used to relay the first live transatlantic TV signal in 1962).

How do you describe the complete signal path of the satellite communications operation?

  1. Begins at a ground station, proceeds to an uplink, then to a downlink, and ends at a receiving ground station.

  2. From the satellite, to a downlink, then to a ground station

  3. Begins at a ground station, proceeds to an uplink, to the satellite itself, to a downlink, and ends at a receiving ground station

  4. All of these


Correct Option: C
Explanation:

A communication satellite works like a relay station where signals transmitted by the ground stations are picked up by the satellite's receiver antennas(uplink), the signals are filtered, their frequency changed and amplified, and then routed via the transmit antennas(downlink) back down to Earth.

The earth area covered by a satellite radio beam is 

  1. Footprint

  2. Bandwidth

  3. Beamwidth

  4. Zone


Correct Option: A
Explanation:

The area of earth covered by radio beam from a satellite dish (transponder) is called satellite footprint.

Which is an application of satellite system?

  1. Whether forecasting

  2. Terrestrial communication

  3. Point to point communication

  4. None of the above


Correct Option: A
Explanation:

Terrestrial communication has two stations with repeaters to strengthen the signal.

Point to point communication means the connection between two end points. e.g. telephone call
Satellites are used for whether forecasting.

Which of the following is not advantage of satellite communication?

  1. can reach over large geographical area

  2. circuit costs independent of distance

  3. broadcast possibilities

  4. none of the above


Correct Option: D
Explanation:

A communications satellite is an artificial satellite that relays and amplifies radio telecommunications signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth.

It has a number of advantages-
1. Mobile communication can be easily established by satellite communication.
2. Satellite communication is economical compared with terrestrial communication particularly where long distances are involved.
3. User has control over their own network.
4. It spreads over a large geographical area.
5. Broadcast over very large distances is possible only due to these satellites.

In which of the following communication methods, the transmitted and receiving antennas can be oriented in any direction?

  1. Ground Wave propagation

  2. Satellite communication

  3. Sky wave propagation

  4. Space wave propagation


Correct Option: B
Explanation:

The direction of transmission and receiving are both fixed in ground wave propagation, sky wave propagation and space wave propagation. However in satellite communication, the antennas are oriented in the required direction depending upon the position of satellite, so that the beam is aligned with the satellite.

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
  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


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- 

  1. $5$ meter

  2. $10$ meter

  3. $15$ meter

  4. $20$ meter


Correct Option: B