Q. Which one of the following is the property of a monochromatic, plane electromagnetic wave in free space
A) Electric and magnetic fields have a phase difference of $\pi/2$
B) The energy contribution of both electric and magnetic fields are equal
C) The direction of propagation is in the direction of $\overrightarrow{B} \times \overrightarrow{E}$
D) The pressure exerted by the wave is the product of its speed and energy density
Explanation
(b) In electromagnetic wave, electric and magnetic fields are in phase
Electromagnetic wave carry energy as they travel through space and this energy is shared equally by electric and magnetic fields
The direction of the propagation of electromagnetic wave is the direction of $\overrightarrow{E} \times \overrightarrow{B}$
The pressure exerted by the wave is equal to its energy density
In electromagnetic wave, the magnitudes of $\overrightarrow{E}$ and $\overrightarrow{B}$ are related by $\frac{E}{B}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.