A student is trying to make an accurate measurement of the wavelength of green light from a mercury lamp ( = 546 nm). Using a

• A student is trying to make an accurate measurement of the wavelength of green light from a mercury lamp (λ = 546 nm). Using a double slit of separation of 0.50 mm, he finds he can see ten clear fringes on a screen at a distance of 0.80 m from the slits. He then tries an alternative experiment using a diffraction grating that has 3000 lines/cm. (i) What will be the width of the ten fringes that he can measure in the first experiment? (ii) What will be the angle of the second-order maximum in the second experiment? (iii) Suggest which experiment you think will give the more accurate measurement of wavelength (l).