Question

Transmission via sky waves is impossible for the frequencies

• A. less than $40MHz$
• B. equal to $40MHz$
• C. more than $40MHz$
• D. all of the above

Answer 1

The correct option is C more than $40MHz$

In radio communication, skywave or skip refers to the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere.

Most long-distance shortwave (high frequency) radio communication—between $3$ and $30MHz$—is a result of skywave propagation.

This $3-30MHz$ is range of frequency which are used in skywaves propogation so that ionosphere is capable of reflecting it.

So, frequency more than $40MHz$ makes it impossible for transmisson via skywave.