A Newton’s Ring Microscope is a precision optical instrument used in physics laboratories to observe and measure Newton’s rings, which are circular interference patterns formed due to the interference of light between a plano-convex lens and a flat glass plate. This experiment helps in determining the wavelength of monochromatic light and the radius of curvature of a lens. The instrument consists of a travelling microscope mounted on a rigid base, along with an arrangement for holding the plano-convex lens and glass plate. When monochromatic light (usually from a sodium lamp) falls on the lens-plate system, a series of bright and dark concentric rings are produced due to the phenomenon of interference of light. These rings are observed and measured using the microscope. The microscope is fitted with cross-wire eyepiece, fine focusing system, and a micrometer scale for precise measurement of the ring diameters. The instrument allows the microscope to move smoothly along a graduated scale with a Vernier, enabling accurate readings. Because of its accuracy and clear observation capability, the Newton’s Ring Microscope is widely used in undergraduate physics laboratories and optical experiments.