Q 12-08-027NEETJEE MainEasy
A plane EM wave travels along the $+x$ direction and its electric field at an instant points along $+y$. At that instant, the magnetic field points along
Answer: (D) $+z$
The direction of travel is along $\vec{E} \times \vec{B}$. With $\vec{E}$ along $\hat{j}$, we need $\hat{j} \times \vec{B} = \hat{i}$, which gives $\vec{B}$ along $\hat{k}$ ($\hat{j} \times \hat{k} = \hat{i}$): the $+z$ direction.
Solution by Sreeraj P, M.Sc Physics