A thin film of thickness 187.5 nm and refractive index 1.6 is coated on plastic of refractive index 1.5. Red light of wavelength 600 nm is incident normally on the film. (a) Determine total path difference between light reflecting from the top and bottom of the film (b) Express path difference in terms of wavelength. (c) what type of interference do we have for the reflected light?

A thin film of thickness 187.5 nm and refractive index 1.6 is coated on plastic of refractive index 1.5. Red light of wavelength 600 nm is incident normally on the film. (a) Determine total path difference between light reflecting from the top and bottom of the film (b) Express path difference in terms of wavelength. (c) what type of interference do we have for the reflected light?