JEE MAIN - Physics (2014 (Offline) - No. 5)
During the propagation of electromagnetic waves in a medium :
Electric energy density is double of the magnetic energy density.
Electric energy density is half of the magnetic energy density.
Electric energy density is equal to the magnetic energy density.
Both electric and magnetic energy of densities are zero.
Explanation
$${E_0} = C{B_0}$$ and $$C = {1 \over {\sqrt {{\mu _0}{\varepsilon _0}} }}$$
Electric energy density $$ = {1 \over 2}{\varepsilon _0}{E_0}^2 = {\mu _E}$$
Magnetic energy density $$ = {1 \over 2}{{{B_0}^2} \over {{\mu _0}}} = {\mu _B}$$
Thus, $${\mu _E} = {\mu _B}$$
Energy is equally divided between electric and magnetic field
Electric energy density $$ = {1 \over 2}{\varepsilon _0}{E_0}^2 = {\mu _E}$$
Magnetic energy density $$ = {1 \over 2}{{{B_0}^2} \over {{\mu _0}}} = {\mu _B}$$
Thus, $${\mu _E} = {\mu _B}$$
Energy is equally divided between electric and magnetic field