Question

When light travels from a rarer to a denser medium, what happens to its speed?

Options

• The speed decreases.

• The speed increases.

• The speed becomes the frequency of oscillation.

• The speed becomes the square of the amplitude.

Answer 1

Light slows down when it travels from a rarer to a denser medium. This reduction in speed does not by itself imply a reduction in the energy carried by the wave.