Question

A wedge shaped film of refractive index μ has thickness t1 and t2 at two points. When a light of wavelength λ falls on the film. The number of changes observed between these two points is m. Find the difference
t2 - t1.
Please help me with this question its very urgent. Please​

Answer 1

Answer:

In thin wedge - shaped film

2μd=nλ

where, μ is refractive index of the film

d is separation between two surfaces

n is number of fringes

λ is wavelength of light

So, here in the problem we are changing the wavelength of the light keeping μ and d same

So, n will change such that nλ will remain same.

so, nn1λ =n2λ2

7×6000=n2 ×4200

⇒n2 =10