Question

the wavelength of green light in vacuum is 504×10-9m. what will be its new wavelength ahen it travels through water?Take refractive index of water as1.33​

Answer 1

Answer:

Refractive Index of a medium = Speed of Light in Vacuum/Speed of Light in medium

As speed = frequency x wavelength and as frequency does not change between mediums

refractive index = wavelength in vacuum / wavelength in medium

wavelength in medium = wavelength in vacuum / refractive index

Refractive Index of air is 1.00029 and of water is 1.3 (given)

Wavelength of Red Light in vacuum ranges from 400 nm to 700 nm (lighter to darker), lets take an average and say 550 nm

So wavelength in air = 550/1.00029 = 549.841 nm

So wavelength in water = 550/1.3 = 423.077 nm

So the change compared to free air in water is = -23.06%