Question

A receiving station on the ground is receiving a signal of frequency $10 \mathrm{MHz}$, then the mode of transmission is (A) ground wave propagation (B) sky wave propagation (C) both ground wave and sky wave propagation (D) neither ground wave nor sky wave propagation

Short answer

The correct answer is (B) sky wave propagation, as the frequency of the received signal, 10 MHz, lies within the effective frequency range of sky wave propagation (3 MHz to 30 MHz) but not within the effective range for ground wave propagation (typically below 3 MHz).

Step-by-step solution

Conclusion for ground wave propagation

Since the frequency is higher than the effective range for ground wave propagation, it is unlikely that the mode of transmission is ground wave propagation. #Step 2: Compare frequency with sky wave propagation# The frequency of the received signal is 10 MHz, which is within the effective frequency range of sky wave propagation (3 MHz to 30 MHz).

Conclusion for sky wave propagation

Since the frequency is within the effective range for sky wave propagation, it is likely that the mode of transmission is sky wave propagation. #Step 3: Select the correct answer# Comparing the given frequency with the properties of ground wave and sky wave propagation, we can rule out ground wave propagation and conclude that the 10 MHz signal is being transmitted via sky wave propagation.

Correct Answer

The correct answer is (B) sky wave propagation.