^Refraction

1. Snell’s law is the law of refraction. It is applicable for both plane & curved surfaces. According to this law the product μ sinθ remains constant in any medium. Thus for a light going from medium 1 to 2

When a light wave enters a denser medium (say glass) from a rarer medium (say air)

2. The frequency (f) of the wave & hence the colour of the light wave remains the same

3. But the wavelength of the wave decreases μ times as a result its speed of the light wave decreases μ  times (because v = f λ)

4. However in refraction of light, the amplitude of light may decrease or remain constant.

5. There is no change of its phase i.e. ΔΦ = 0.

6. No. of waves in ‘t’ thickness of a medium are