Q1. Consider a plane wave of monochromatic green light, 600 nm that is incident normally on two identical narrow slits. The slits are separated by a distance of 30um. An interference pattern is observed on a screen located a distance away from the slits. On the screen location nearest the central maximum where the intensity is zero is found to be 1.5 cm from this central point. What is the distance to the screen?

Q2. A diffraction grating with 330 {rm lines/mm} is 1.00 {rm m} in front of a screen. What is the wavelength of light whose first-order maxima will be 17.0 {rm cm} from the central maximum on the screen?