Question

Gradient of refractive index is ____________

(a) Change in the refractivity with respect to height

(b) Change in the height with respect to refractivity

(c) Change in the refractivity with respect to Pressure

(d) Change in the refractivity with respect to temperature

This question was addressed to me in an interview for internship.

This key question is from Space Wave Propagation in section Space Wave Propagation of Antennas

Answer 1

Right answer is (a) Change in the refractivity with respect to height

For explanation: Change in the refractivity with respect to height is known as the gradient of refractive index. Radio horizon varies with the refractive index in the atmosphere.