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What is the minimum thickness of thin fi...

What is the minimum thickness of thin film required for constructive interference in the reflected light through it ?
(Given, the refractive index of the film `=1.5,` wavelength of the lilght incident on the film `=600` nm.

A

`100 nm`

B

`150 nm`

C

`200 nm`

D

`250nm`

Text Solution

Verified by Experts

The correct Answer is:
B
`2 mu t cos r = (2n + 1) (d)/(2)` for minimum thickness `t = (lambda)/(4 mu cos r) = 150 nm`
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