Question

When a beam of light, originally traveling in air, enters a piece of glass having an index of refraction of 3/2, its frequency

A) Increases by a factor of 3/2

B) Is reduced to 2/3 it's original value

C) Is unaffected

Answer 1

The expression for the wavelength in air is,

\(\lambda_{\operatorname{air}}=\frac{c}{f} \ldots(1)\)

The expression for the wavelength in glass medium is,

\(\lambda_{\text {gins }}=\frac{v}{f} \ldots(2)\)

By using the above two equations we coclude that the frequency is same for the two cases. Because of the frequency doesn t change as light moves from one medium to another.

Therefore, the correct option is \((C)\) is unaffected.