When light is incident on a soap film of thickness `5xx10^(-5)` cm, the wavelength of light reflected maximum in the visible region is 5320 Å. Refractive index of the film will be,

Options

A. 1.22
B. 1.33
C. 1.51
D. 1.83

Answer

A, C

Explanation

The condition for constructive interfernence, (for reflection)
`2murcosr=(2n+1)(lambda)/(2) " " [thereforecosr=1]`
`mu = ((2n + 1)lambda)/(4r)`
For visible region, n = 2
`mu=((2(2)+1)xx5320xx10^(-10))/(4xx5000xx10^(-10))=0.5xx10^(-7)`
`lambda = 500 Å`