Question

In waveguides, which of the following conditions will be true?

(a) V > c

(b) V < c

(c) V = c

(d) V >> c

I had been asked this question during an internship interview.

The above asked question is from Dielectric vs Conductor Wave Propagation in chapter EM Wave Propagation of Electromagnetic Theory

Answer 1

Right choice is (a) V > c

To elaborate: In waveguides, the phase velocity will always be greater than the speed of light. This enables the wave to propagate through the waveguide. Thus V > c is the required condition.