Question

The ratio of the magnitudes of the electric field and magnetic field of a plane electromagnetic wave is ______.

Options

• 1

• `1/c`

• c

• `1/c^2`

Answer 1

The ratio of the magnitudes of the electric field and magnetic field of a plane electromagnetic wave is c.

Explanation:

The magnetic energy density is equivalent to the electrical energy density of an EM wave. EM waves are distinct from other waves in that they do not require any medium to propagate. The magnitude of an EM wave's propagation velocity is equal to the speed of light c.