Q. The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is : (c = speed of electromagnetic waves)
A) 1 : 1
B) 1 : c
C) 1 : $c^2$
D) c : 1
Explanation
[Solution] The average energy densities of the electric and magnetic fields are equal ($\frac{1}{2}\epsilon_0E^2 = \frac{B^2}{2\mu_0}$), so they contribute equally (1 : 1). The source key gives (3), which is incorrect. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.