Q 12-08-238JEE MainJEE Main 2025 (7 Apr, Shift 2)Easy
The unit of $\sqrt{\dfrac{2I}{\epsilon_0c}}$ is: ($I$ = intensity of an electromagnetic wave, $c$ = speed of light)
Answer: (D) $\text{N C}^{-1}$
The intensity of an EM wave is $I = \tfrac12\epsilon_0E_0^2c$, so
$$\sqrt{\frac{2I}{\epsilon_0c}} = E_0$$
the amplitude of the electric field, with unit $\text{N C}^{-1}$.
Solution by Sreeraj P, M.Sc Physics