Question

Sky wave communication is based upon

• A. reflection by ionosphere
• B. absorption by ionosphere
• C. transmission through ionosphere
• D. none of these

Answer 1

The correct option is A

reflection by ionosphere

Explanation for the correct option:

1. Ionosphere is the uppermost part of the atmosphere.
2. It is the boundary between the vacuum of space and the earth.
3. It is ionized (thus the name) by solar radiation.
4. Electromagnetic waves above the frequency of microwaves do not get reflected by the ionosphere.
5. The ions in the ionosphere reflect the radio waves sent from one part of the earth to another thus facilitating the broadcast of information beyond the horizon.

Hence, option A is correct.