Question

A parallel beam of light (λ = 5890 Å) strikes a film of oil (μ = 1.46). If 8th dark ring be

seen, when viewed at an angle of 30° to the normal, calculate the thickness of the film.​

Answer 1

$\huge\bigstar\underline\pink{Answer}$

★ Directly apply formula

n.lembda = 2μt cos r

where,

n = 8

lembda = wavelength = 5890A°

μ= refrective index = 1.46

cos r = 30° = √3/2

now, substitute these values in above formula.

Rest is calculation, you can do yourself

$\huge\pink{\ddot{\smile}}$

Answer 2

Answer:

by direct formula we can solve this problem

hence solution is given above