A double slit experiment is performed with light of wavelength 500 ~nm . A thin film of thickness 2 m and refractive index 1.5 is introduced in the path of the upper beam. The location of the central maximum will

Step-by-step solution

Wavelength =500 ~nm =500 10⁻⁹ ~m Thickness of the film, t=2 m =2 10⁻⁶ ~m Refractive index =1.5 When there is no thin film placed in the path of any one of the two beams, the path difference between them is given by d y / D (considering the two beams meetings at a point P) . In case we put a thin film in the path of one of the beams, then the optical path of that beam gets longer. Now for the central maximum, path difference in absence of the film is x=0 . But when we put the film, the path difference becomes aligne