Question

Which property of light does not change when it travels from one medium to another?

• A. Frequency and phase
• B. Speed
• C. Wavelength
• D. Amplitude

Answer 1

The correct option is A

Frequency and phase

1. The frequency and phase of light do not change when it travels from one medium to another.
2. Frequency is a property of the source that emits the light, not the medium via which it is propagated.
3. As a result, the frequency does not change when light moves from one medium to another that is separated by a sharp border.
4. When light enters another medium, the distance between particles changes which in turn changes the path of light.
5. Due to changing paths, the speed of light changes.
6. But the other properties like amplitude and wavelength of light change in refraction.

Hence, option A is correct.