Answer to Question #76889 in Optics for Shreen

Question

Why does the frequency not change when refraction occurs? It has to change as the wavelength becomes shorter, causing more waves to pass in a second. Right?

Answer 1

Frequency is number of waves passing through a point in given time period. Wavelength is distance between the two neighboring crest or trough.
When light travels from one medium to another only speed of the light and wavelength changed and frequency does NOT change, it remains constant in all medium. The speed of light and wavelength changes in order to maintain the constant frequency.
For example:
1) When light travels from optically rear to denser medium, as you know speed of the light decreases and wavelength length also decreases which gives out same frequency.
2) When light travels from optically denser to rear medium, speed of light increases and wavelength increases as whole frequency is same.