Q 12-08-172JEE MainJEE Main 2021 (27 Aug, Shift 1)Easy
The electric field in a plane electromagnetic wave is given by, $E = 50\sin(500x - 10\times10^{10}t)$ V m$^{-1}$. The velocity of an electromagnetic wave in this medium is: (Given $c = $ the speed of light in vacuum).
Answer: (D) $\frac{2}{3}c$
$v = \dfrac{\omega}{k} = \dfrac{10\times10^{10}}{500} = 2\times10^8$ m s$^{-1}$ $= \dfrac{2}{3}c$.
Solution by Sreeraj P, M.Sc Physics