Q 12-08-190JEE MainJEE Main 2020 (4 Sep, Shift 2)Medium
The electric field of a plane electromagnetic wave is given by $\vec E = E_0(\hat x + \hat y)\sin(kz - \omega t)$. Its magnetic field will be given by
Answer: (A) $\dfrac{E_0}{c}(-\hat x + \hat y)\sin(kz - \omega t)$
The wave travels along $+\hat z$, and $\vec B = \dfrac1c\hat z\times\vec E$ (in phase with $\vec E$):
$$\vec B = \frac{E_0}{c}(\hat z\times\hat x + \hat z\times\hat y)\sin(kz - \omega t) = \frac{E_0}{c}(\hat y - \hat x)\sin(kz - \omega t)$$
Solution by Sreeraj P, M.Sc Physics