In a Young’s double-slit experiment, the slits are separated by 0.30 mm and the screen is placed 1.8 m away. The experiment is performed with monochromatic light of wavelength 550 nm.
A transparent thin film of refractive index 1.50 and thickness 2.2 μm is introduced in front of one of the slits so that the entire beam from that slit passes through the film.
a) Calculate the additional optical path introduced between the two interfering beams due to the film.
b) Determine the number of bright fringes that will cross the central point O on the screen as a result of inserting the film.
c) After the film is inserted, find the linear displacement on the screen of the original central bright fringe. State clearly in which direction (towards which slit) this displacement occurs.