Total energy of density of electromagnetic waves in vacuum is given by the relation

Options

A. `1/2.(E^(2))/(epsi_(0)) + (B^(2))/(2mu_(0))`
B. `1/(2)epsi_(0)E^(2) + 1/2mu_(0)B^(2)`
C. `(E^(2) + B^(2))/(c)`
D. `(1)/(2) epsi_(0)E^(2) + (B^(2))/(2mu_(0))`

Answer

D

Explanation

The energy in EM waves is divided equally between the electric and magnetic fields.
The total energy per unit volume is `u - u_(e) + u_(m)`
`1/2 epsi_(0)E^(2) + 1/2 (B^(2))/(mu_(0))`