Three waves A, B and C of frequencies 1600 kHz, 5 MHz and 60 MHz, respectively are to be transmitted from one place to another. Which of the following is the most appropriate mode of communication?

Question

Philoid · Accepted Answer

A ground wave has frequency of a few megahertz (a few thousand kilohertz). A sky wave has frequency from a few megahertz to 30-40 MHz A space wave carries frequencies above 40 MHz

Now, clearly wave C has frequency more than 40 MHz. Hence, it is transmitted via a space wave. We can eliminate (a) and (c). Now, a has frequency below 40 MHz (1600kHz = 1.6 MHz). Hence, A cannot be transmitted via a space wave. Hence, we can eliminate (d). The only option left is (b). Also, we can see that A has a frequency of only a few MHz. Hence, A is transmitted via a ground wave as is stated in (b).