Question

Which of the following statement is wrong?

• A. Ground wave propagation can be sustained at frequencies $500\, kHz$ to $1,500\, kHz$
• B. Satellite communication is useful for the frequencies above $30 \,MHz$
• C. Sky wave propagation is useful in the range of $30$ to $40\, MHz$
• D. Sky wave propagation takes place through tropospheric space
• E. The phenomenon involved in sky wave propagation is total internal reflection.

Answer 1

Answer: (C)

In ground wave propagation, radiowaves travel along the surface of the earth (following the curvature of earth). Ground wave propagation can be sustained only at low frequencies ( $ \tilde{\ }500\text{ }kHz $ to $ 1500\text{ }kHz $ ) or for radiobroadcast at long wavelengths. Satellite communication is useful for the frequencies above 30 MHz which takes place through tropospheric space. The phenomenon involved in the sky wave propagation is total internal reflection.