(a) Interference fringes are produced on a screen by double-slit interference using light of wavelength 650 nm. The fringe separation is 5.0 mm and the separation of the slits is 0.75 mm. Find the distance between the double slit and the screen. (3 marks) (b) A slit of width, (1 is illuminated by a white light. Find: (i) the rst minimum for red light of wavelength 1 = 650 nm appear at 0 = 15 (2 marks) (ii) the wavelength of the light whose rst side diffraction maximum is at 15. thus coincide with the rst minimum for the red light (2 marks) (c) An unpolaiised light with intensity In is sent through 2 polarisers. Discover the angle of the second polariser to be rotated so that the intensity of the transmitted light is 0.25 10