Question

A beam of red and blue light in air is incident at 30º on a glass surface. Which is true?

a. The blue light is bent toward the normal more than the red light.
b. The blue light is bent toward the normal less than the red light.
c. The blue light is bent away from the normal more than the red light.
d. The blue light is bent away from the normal less than the red light.

Answer 1

a. The blue light is bent toward the normal more than the red light.

Step-by-step explanation:

When light travels from a less dense medium, in this case air into a denser medium (glass) it is bent towards the normal because of the reduction in speed due to the dense medium.In this scenario we have the same incident angle of 30º. therefore, we consider the wavelength of the light because at shorter wavelengths we have more refraction occurring as compared to longer wavelengths. We know that Blue light has a shorter wavelength as compared to red light, which means it will bend toward the normal more than the red light.