The wavelength of green colour in air and violet colour in water are 5381 Å and 3042 Å respectively. If the wavelength of green colour in water is the same as the wavelength of violet colour in air, find its value. (Assume that refractive index for green and violet colour is approximately same)

Options

A. 4046 Å
B. 3046 Å
C. 3000 Å
D. 2000 Å

Answer

A

Explanation

`mu_(g) = mu_(v)`
`(lambda_(ga))/(lambda_(gw)) = (lambda_(va))/(lambda_(vw))`
`(5381)/(lambda_(va)) = (lambda_(va))/(3042)`
`:. (lambda_(va))^(2) = 5381 xx 3042`
`:. lambda_(va) = 4046 Å`