Q. The ratio of amplitude of magnetic field to the amplitude of electric field for an electromagnetic wave propagating in vacuum is equal to :
A) the speed of light in vacuum
B) reciprocal of speed of light in vacuum
C) the ratio of magnetic permeability to the electric susceptibility of vacuum
D) unity
Explanation
[Solution from source] In vacuum E₀ = cB₀, so B₀/E₀ = 1/c, the reciprocal of the speed of light. The speed of light itself is the ratio E₀/B₀, the reverse. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.