Chapter 28, Problem 36PCE

Predict/Calculate Newton s Rings Monochromatic light with λ = 648 nm shines down on a plane-convex lens lying on a piece of plate glass as shown in Figure 28-47. When viewing from above one sees a set of concentric dark and bright fringes referred to as Newton’s rings (See Figure 28-13 (b) for a photo of Newton’s rings.) (a) If the radius of the twelfth dark ring from the center is measured to be 1.56 cm, what is the radius of curvature R, of the lens? (b) If light with a longer wavelength is used with this system, will the radius of the twelfth dark ring be greater than or less than 1.56 cm? Explain.