A parallel beam of light of wavelength 560 nm falls on a thin film of oil (refractive index = 1.4). What should be the minimum thickness of the film so that it strongly reflects, the light?

Question

Philoid · Accepted Answer

Given, refractive index

Wavelength of light, .

Let be the thickness of the film

For the bubble to reflect light strongly, the condition is

Now, d would be minimum for n=0,

Therefore,