Question

A: The maximum range of coverage by ground wave propagation is limited to a few $MHz$
R: The attenuation of the ground wave increases very rapidly with frequency.
$A$ Assertion and reason are true and reason is the correct explanation of assertion.
$B$ Assertion and reason are true but reason is not the correct explanation of assertion.
$C$ Assertion is true but reason is false.
$D$ Assertion is false but reason is true.

Answer 1

Hint: Ground wave propagation is one of the methods of propagating electromagnetic waves from one point to another point, in ground wave propagation radio waves, which are basically electromagnetic waves of frequency range $30\;Hz$ to $30\;GHz$, are transmitted over the surface of earth in the region between ionosphere and surface of earth.

Complete step by step answer:
The maximum range of coverage by ground waves is limited to a few $MHz$ because in ground wave propagation as the frequency is increased the attenuation of waves increases very rapidly, attenuation is the process of decrease in intensity of a wave as it travels through a medium, as the wave travels it is scattered by the particles of medium which causes intensity loss and hence the range of coverage by ground wave propagation is limited to a few $MHz$.

So, the correct answer is “Option A”.

Additional Information: There are two more ways in which radio waves can be transmitted one is space wave propagation and other is sky wave propagation. In space wave propagation radio waves are transmitted from transmitting antenna and they directly reach receiving antenna through space, waves travel in straight line from transmitting antenna to receiving antenna. In sky wave propagation the radio waves are sent from ground they are reflected from the ionosphere and are received back on the ground.

Note: The frequency range for all three kinds of ways of wave propagation is different but the ranges also overlap each other, also the term fading of waves can also be used instead of attenuation, the major difference between fading and attenuation is that attenuation is due to power loss while transmission, while fading is due to phase difference created when waves are received from different paths.