A monochromatic (single frequency, single wavelength) light ray in air (n = 1) enters a glass prism (n = 1.5). In the glass prism
A) both the frequency and the wavelength are the same as in air
B) the frequency is the same, but the wavelength is greater than in air.
C) the frequency is the same, but the wavelength is smaller than in air.
D) the wavelength is the same, but the frequency is greater than in air.
E) the wavelength is the same, but the frequency is smaller than in air.

Question

Quizplus · Accepted Answer

When light passes from one medium to another, the speed of the light changes, which causes the wavelength and frequency of the light to change. In this case, the light ray enters a medium with a higher refractive index (glass) from a medium with a lower refractive index (air). This causes the light ray to bend towards the normal (an imaginary line perpendicular to the surface of the prism) since the speed of light is slower in the glass than in air.
Due to the decrease in the speed of the light, the wavelength becomes shorter in the glass prism than in air. Therefore, the correct option is C, where the frequency is the same, but the wavelength is smaller than in air.

A Monochromatic (Single Frequency, Single Wavelength) Light Ray in Air