The time averaged energy in a sinusoidal electromagnetic wave is:
A)overwhelmingly electrical
B)slightly more electrical than magnetic
C)equally divided between the electric and magnetic fields
D)slightly more magnetic than electrical
E)overwhelmingly magnetic

Question

Quizplus · Accepted Answer

The time-averaged energy in a sinusoidal electromagnetic wave is equally divided between the electric and magnetic fields. This is due to the fact that the energy density of the electric field is proportional to the square of the electric field strength, while the energy density of the magnetic field is proportional to the square of the magnetic field strength. Since the electric and magnetic fields are perpendicular to each other in an electromagnetic wave, their magnitudes are equivalent and thus both contribute equally to the total energy density.

The Time Averaged Energy in a Sinusoidal Electromagnetic Wave Is