JEE Main 2022 — Electromagnetic Waves Question with Solution

The ratio of electric field amplitude to the magnetic field amplitude of an electromagnetic wave is equal to the speed of light in the medium. Therefore,

$$\begin{gathered} c=\frac{E_0}{B_0} \\ \Rightarrow E_0=c{B}_0 \end{gathered}$$

$\Rightarrow E_0=3\times {10}^8\times 2\times {10}^{-8}$

$\Rightarrow E_{\mathit{0}}=6 \mathrm{V} {\mathrm{m}}^{-1}$

According to the given equation $\overrightarrow{B}=2\times {10}^{-8}\sin \left(0.5\times {10}^{3}x+1.5\times {10}^{11}t\right)\hat{\mathrm{j}} \mathrm{T}$ the wave travels in $x$ direction. As electric field and magnetic field vibrate perpendicular to the velocity of light, electric field can not be along $x$ axis.