In a diffraction experiment, red light of wavelength 600 nm passes through a diffraction grating. On a screen 1.5 m away, the distance between the centre (zeroth) bright band and the tenth-order bright band is 13.2 cm. a. What is the separation of the slits? [2 marks] b. Determine the number (N) of lines that are contained in a centimeter of the diffraction grating. (That is, write your answer in lines/cm.) [2 marks] c. Would increasing the density of lines change what angle the fringes occur at? Show proof. [2 marks]