Advertisements
Advertisements
प्रश्न
State the factors which limit its range of propagation
उत्तर
Factors which limit the range of propagation:
(a) At frequencies higher than 40 MHz, the space waves scatter more easily and the communication is limited to line-of-sight propagation.
(b) Because of the line-of-sight nature of propagation, direct waves get blocked at some point by the curvature of the Earth.
APPEARS IN
संबंधित प्रश्न
What is space wave propagation?
Derive an expression for the maximum line of sight distance between two antennas for space wave 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?
The reflected waves from an ionosphere are _____.
(a) ground waves
(b) sky waves
(c) space waves
(d) very high-frequency waves
Describe briefly, by drawing suitable diagram, the sky wave ?
Answer the following question.
On what factors does the range of coverage in ground wave propagation depend?
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?
The radio wave of frequency 300 MHz to 3000 MHz be.long to
The characteristic impedance of a coaxial cable is of the order of
A TV transmission tower has a height of 240 m. Signals broadcast from this tower will be received by LOS communication at a distance of (assume the radius of earth to be 6.4 × 106 m)
- 100 km
- 24 km
- 55 km
- 50 km