Question

The phase velocity of a wave having a phase constant of 4 units and a frequency of 2.5 x 10^9 radian/sec is (in 10^8 order)

(a) 3.25

(b) 3.75

(c) 6.25

(d) 6.75

The question was posed to me during a job interview.

This is a very interesting question from Phase and Group Velocity in section Waveguides of Electromagnetic Theory

Answer 1

Right option is (c) 6.25

The explanation is: The phase velocity and the phase constant are related by Vp = ω/βg. On substituting for ω = 2.5 x 10^9 and β = 4, we get the phase velocity as 6.25 units.