Q. For a plane electromagnetic wave propagating in x-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?
A) $-\hat{j}+\hat{k}, -\hat{j}-\hat{k}$
B) $\hat{j}+\hat{k}, -\hat{j}-\hat{k}$
C) $-\hat{j}+\hat{k}, -\hat{j}+\hat{k}$
D) $\hat{j}+\hat{k}, \hat{j}+\hat{k}$
Explanation
[Solution] $\vec{E} \times \vec{B}$ must point along +x: $(-\hat{j}+\hat{k}) \times (-\hat{j}-\hat{k}) = 2\hat{i}$. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.