It has been proposed that automobile windshields and headlights should have polarising filters to reduce the glare of oncoming lights during night driving. Would this work? How should the polarising axes be arranged? What advantages would this scheme have? what disadvantages?

Athin plastic sheet of refractive index 1.6 is used to cover one of the slits of a double slit arrangement. The central point on the screen is now occupied by what would have been the 7" bright fringe before the plastic was used. If the wavelength of light is 600 nm, what is the thickness (in um) of the plastic?

A thin plastic of refractive index 1.6 is used to cover one of the slits of a double slit arrangement. The central point omn the screen is now occupied by what would have been the 7th bright fringe before the plastic was used. If the wavelength of light is 600 nm, what is the thickness ( in mu m ) of the plastic?