A plano concave lens having index of refraction 1 50 is

Last updated: 6/26/2023

A plano concave lens having index of refraction 1 50 is placed on a flat glass plate as shown in Figure P37 64 Its curved surface with radius of curvature 8 00 m is on the bottom The lens is illuminated from above with yellow sodium light of wavelength 589 nm and a series of con centric bright and dark rings is observed by reflection The interference pattern has a dark spot at the center sur rounded by 50 dark rings of which the largest is at the outer edge of the lens a What is the thickness of the air layer at the center of the interference pattern b Calcu late the radius of the outermost dark ring c Find the focal length of the lens