Question

Which of the following frequencies will be suitable for beyond-thehorizon communication using sky waves?

(a) 10 kHz
(b) 10 MHz
(c) 1 GHz
(d) 1000 GHz

Answer 1

$\large{\underline{\boxed{\sf QUESTION}}}$

Which of the following frequencies will be suitable for beyond-thehorizon communication using sky waves?

(a) 10 kHz

(b) 10 MHz

(c) 1 GHz

(d) 1000 GHz

$\large{\underline{\boxed{\sf ANSWER}}}$

Answer is a) 10 MHz.

For beyond-the-horizon communication, the signal waves needs to travel a large distance. 10 KHz signals cannot be used as it cannot be radiated efficiently due to limitation of the antenna size. The high energy signal waves (1GHz − 1000 GHz) can penetrate the ionosphere.

On the other hand, 10 MHz frequencies get reflected easily from the ionosphere. Therefore, signal waves of such frequencies are suitable for beyond-the-horizon communication.