A wedge-shaped film of air is made by placing a small slip of paper between the edges of two flat glass plates at one end of these plates, while the glass plates touch at the other end. Light of wavelength 650 nm is incident normally on the glass plates, the interference bands are observed by reflection.
A) Is the first band near the point of contact of the glass plates dark or light? Why?
B) If there are five dark bands per centimeter, what is the angle of the wedge?