Question

Which one is the better propagation mode to propagate television frequency and radar signals?
(A) Satellite communication
(B) Ground propagation
(C) Polarized communication
(D) Sky-wave communication

Answer 1

Hint
Propagation mode is determined by the frequency of the application. For high frequencies some communication modes cannot work, and vice versa.

Complete step by step answer
Communication is the process of transfer of information in the form of signals from the sender to the receiver. Similarly, a communication system is a network of transmission systems, relay stations, tributary stations, and terminal equipment usually capable of interconnection and interoperation.
Based on the medium of transmission and the type of signal to be transmitted, the modes of propagation of signals vary. For example, the ground-wave propagation uses the area between the surface of the earth and the ionosphere. It is optimal for signals having a frequency range in the low and medium frequency portion of the radio spectrum.
Polarized communication mode is mostly wireless and is used as a method for polarized antenna transmission using a differential technique. Sky-wave propagation is a type of radio communication used for radio waves reflected or refracted back to the Earth’s surface from the ionosphere.
Televisions and radar signals operate in the high and ultra-high frequency range. Hence, communication satellites are used to relay and amplify the radio telecommunication systems using a transponder.
Hence, the mode of propagation for television is option (A); Satellite communication.

Note
Satellite communication is also readily used for mobile and wireless communication applications independent of the location. Since it has a long range and operates from the orbit of the Earth, a wide area can be covered by just one satellite, but there can be some propagation delays.