Advertisements
Advertisements
Question
Mention three different modes of propagation used in communication system.
Solution
Three modes of propagation of electromagnetic waves,
(a) Ground waves,
(b) Sky waves,
(c) Space waves.
Sky wave propagation is used for long distance communication by ionospheric reflection of radio waves.
RELATED QUESTIONS
What is space wave propagation?
State the factors which limit its range of propagation
Is it necessary for a transmitting antenna to be at the same height as that of the receiving antenna for line-of-sight communication? A TV transmitting antenna is 81m tall. How much service area can it cover if the receiving antenna is at the ground level?
State three components of space wave propagation.
The reflected waves from an ionosphere are _____.
(a) ground waves
(b) sky waves
(c) space waves
(d) very high-frequency waves
Is it necessary for a transmitting antenna to be at the same height as that of receiving antenna for LOS communication ?
Answer the following question.
In the skywave mode of propagation, why is the frequency range of transmitting signals restricted to less than 30 MHz?
Name the three different modes of propagation in a communication system. State briefly why do the electromagnetic waves with a frequency range from a few MHz up to 30 MHz can reflect back to the earth. What happens when the frequency range exceeds this limit?
An antenna is
In He-Ne loser the most favourable ratio of Helium toNe on for satisfactory laser action is
