Q 12-08-058JEE MainJEE Main 2024 (27 Jan, Shift 1)Easy
A plane electromagnetic wave propagating in $x$-direction is described by
$$E_y = (200\ \text{V m}^{-1})\sin\left[1.5\times10^7 t - 0.05x\right]$$
The intensity of the wave is: (Use $\epsilon_0 = 8.85\times10^{-12}\ \text{C}^2\,\text{N}^{-1}\,\text{m}^{-2}$)
Answer: (B) $53.1\ \text{W m}^{-2}$
$$I = \frac12\epsilon_0 c E_0^2 = \frac12\times8.85\times10^{-12}\times3\times10^8\times(200)^2$$
$$I = \frac12\times8.85\times10^{-12}\times1.2\times10^{13} = 53.1\ \text{W m}^{-2}$$
Solution by Sreeraj P, M.Sc Physics