Question

The effective radius of earth is how many times the actual radius of earth at standard atmospheric conditions?

(a) 3/4

(b) 4/3

(c) 1/4

(d) 1/3

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

This intriguing question originated from Radio Wave Propagation in section Radio Wave Propagation of Antennas

Answer 1

The correct choice is (a) 3/4

For explanation I would say: Effective radius of earth is the equivalent radius of earth used to correct atmospheric refraction as the refractive index varies linearly with height. It is 4/3 times the geometrical radius of the earth.