The energy density of an electromagnetic wave is
A) entirely in the electric field.
B) entirely in the magnetic field.
C) 1/4 in the electric field and 3/4 in the magnetic field.
D) 1/4 in the magnetic field and 3/4 in the electric field.
E) equally divided between the magnetic and the electric fields.

Question

Quizplus · Accepted Answer

The energy density of an electromagnetic wave is evenly distributed between the magnetic field and the electric field. This is based on the fact that the energy in an electromagnetic wave is proportional to the square of the electric and magnetic fields and that these fields are orthogonal to each other. Therefore, the energy will be equally distributed between them.

The Energy Density of an Electromagnetic Wave Is