Question 1

What is refraction of light?

Accepted Answer

Bending of light due to change in speed in a new medium. Refraction is the bending of light because its speed changes in a different medium. It occurs at the boundary between two transparent media. The frequency of light stays the same during refraction.

Question 2

Which statement represents Snell’s law for refraction from medium 1 to medium 2?

Accepted Answer

n1 sin i = n2 sin r. Snell’s law is n1 sin i = n2 sin r for a fixed pair of media. It links angles with refractive indices. It is valid for a given wavelength and uniform media.

Question 3

How is refractive index n related to speed of light in a medium?

Accepted Answer

n = c/v. Refractive index is defined as n = c/v. Here c is speed of light in vacuum and v is speed in the medium. Larger n means smaller speed in that medium.

Question 4

A ray goes from air into glass. How does it bend?

Accepted Answer

Towards the normal. When light enters a denser medium like glass, its speed decreases. The ray bends towards the normal in this case. For the reverse path, it bends away from the normal.

Question 5

Which quantity remains unchanged when light refracts from one medium to another?

Accepted Answer

Frequency. Frequency of light remains the same during refraction. Speed and wavelength change when the medium changes. This is because frequency is set by the source.

Refraction — Set 1