1. How many bright fringes appear between the first diffraction-envelope minima to either side of the central maximum in a double-slit pattern if the wavelength of the light λ is 550 nm, the thickness of the slitsd is 0.150 mm, and the distance between theslits a is 30.0 mm?
2. What is the ratio of the intensity of the third bright fringe to the intensity of the centralfringe?