Question

High frequency waves are:
A) Absorbed by F layer
B) Reflected by the E layer
C) Capable of use for long distance transmission
D) Affected by the solar cycle

Answer 1

Hint: As we know that the high frequency waves are the communication for many years. As we know the sky waves system was the backbone of our long communication. The satellite brought a change of philosophy about long distance communication.

Complete solution:
In this question, High frequency waves are.
The ultraviolet rays are expanding their energy and the different wavelengths. The different layers in the atmosphere are caused by the different wavelengths of rays. Thus, the different ionosphere layers have a high variable source of ionizing agents, solar wind.

Thus, the ionosphere is expanding around $400\,{\text{km}}$ above the earth. These regions of the radiation from the sun cause the molecules to ionize automatically. There the ionization levels depend on different altitude and as a result. There is ionization expending the expanding ionosphere and the layers being peaks in levels of ionization. These regions are temporarily the free electrons that vibrate the incoming signals and cause them to be refracted according to their frequency.

The feeling was, "HF is dead." People were eager to switch to satellites because of the simplicity of operations. No longer did we have to study the ionosphere or calculate what frequency would work. In satellite communications all you had to know was which direction to point your antenna and what channel to use.

High frequency waves are used for large distance communication through skip wave or sky wave propagation. These waves are to be reflected by the E layer of the ionosphere.

Note: As we know that the stratosphere lies between the troposphere and the ionosphere, about $11$ to $48\;{\text{km}}$ $\left( {7 - 31\;miles} \right)$ above the earth. The temperature in this region is more nearly constant than in the troposphere.