Question

Two waves A and B of frequencies 2 MHz and 3 MHz, respectively are beamed in the same direction for communication via sky wave. Which one of these is likely to travel longer distance in the ionosphere before suffering total internal reflection?

Answer 1

The refractive index increases with an increase in frequency which implies that for higher frequency waves, the angle of refraction is less, i.e. bending is less. Hence, the condition of total internal reflection is attained after travelling a larger distance (by 3 MHz waves).