Q 12-08-065JEE MainJEE Main 2024 (30 Jan, Shift 1)Easy
The electric field of an electromagnetic wave in free space is represented as $\vec E = E_0\cos(\omega t - kz)\,\hat i$. The corresponding magnetic induction vector will be:
Answer: (B) $\vec B = \dfrac{E_0}{C}\cos(\omega t - kz)\,\hat j$
The wave travels along $+z$ (phase $\omega t - kz$), and $B$ is in phase with $E$ with $B_0 = E_0/C$. The direction of propagation is $\hat E\times\hat B$: $\hat i\times\hat j = \hat k$, so $\vec B$ is along $\hat j$:
$$\vec B = \frac{E_0}{C}\cos(\omega t - kz)\,\hat j$$
Solution by Sreeraj P, M.Sc Physics