Question

a beam of light of wavelength 4320a° is incident on a thin film of refractive index 1.5 such that the angle of refraction is 50°. Find the smallest thickness of the thin film which will appear dark by reflection ?

Answer 1

Answer:

I don't know brother.

Explanation:

Please help

Answer 2

Answer:

2.24*10^-7m

Explanation: To obtain dark region

$2\mu t cosr = n\lambda$