Q. An em wave is propagating in a medium with a velocity $\vec{V} = V\hat{i}$. The instantaneous oscillating electric field of this em wave is along +y axis. Then the direction of oscillating magnetic field of the em wave will be along
A) -y direction
B) +z direction
C) -z direction
D) -x direction
Explanation
[Solution] $\vec{E} \times \vec{B}$ is along $\hat{i}$: $\hat{j} \times \hat{k} = \hat{i}$, so B is along +z. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.