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

Options

A. `A` is transmitted via space wave while `B` and `C` are transmitted via sky wave.
B. `A` is transmitted via ground wave, `B` via sky wave and `C` via space wave.
C. `B` and `C` are transmitted via ground wave while `A` is transmitted via sky wave.
D. `B` is transmitted via ground wave while `A` and `C` are transmitted via space wave.

Answer

B

Explanation

Ground wave propagation is suitable for the frequencies upto `2 MHz` (less than few `mHz`)
Sky wave propagation is suitable for the sequencies upto `30` to `40 MHz`
The space wave propagation is suitable for the freequencies above `40 MHz`.