Q 12-08-083JEE MainJEE Main 2023 (24 Jan, Shift 1)Medium
If $\vec E$ and $\vec K$ represent electric field and propagation vectors of the EM waves in vacuum, then magnetic field vector is given by ($\omega$ = angular frequency)
Answer: (A) $\dfrac1\omega\vec K\times\vec E$
From Faraday's law for a plane wave, $\vec K\times\vec E=\omega\vec B$, so $\vec B=\dfrac1\omega\vec K\times\vec E$. (Check: $|B|=\dfrac{KE}{\omega}=\dfrac Ec$.)
Solution by Sreeraj P, M.Sc Physics