The energy density associated with electric field $$\vec{E}$$ and magnetic field $$\vec{B}$$ of an electromagnetic wave in free space is given by ($$\varepsilon_0$$ - permittivity of free space, $$\mu_0$$ - permeability of free space)

A

$$U_E = \dfrac{E^2}{2\varepsilon_0}$$, $$U_B = \dfrac{B^2}{2\mu_0}$$

B

$$U_E = \dfrac{\varepsilon_0 E^2}{2}$$, $$U_B = \dfrac{B^2}{2\mu_0}$$

C

$$U_E = \dfrac{\varepsilon_0 E^2}{2}$$, $$U_B = \dfrac{\mu_0 B^2}{2}$$

D

$$U_E = \dfrac{E^2}{2\varepsilon_0}$$, $$U_B = \dfrac{\mu_0 B^2}{2}$$