When a plano-convex lens is placed on the top of a flat glass surface a thin air film is formed between the two surfaces as shown in the figure. By employing sodium light whose mean wavelength is 5893Å, R can Ans: Diameter of a ring depends on the wavelength of light used, refractive index of the medium between lens and glass plate, order of the ring and radius of curvature of Planocovex lens. Q. In this case, the radius of curvature of the convex surface of the given lens is supplied or is determined otherwise. Objective – To determine the wavelength of sodium light using Newton’s ring method. EXPERIMENT No. EXPERIMENT: 4 Object: To find the wavelength of Sodium light by Newton’s ring. The thickness of air film varies from zero at the point of contact to some value t at point P. Describe how does the Newton’s ring changes when air medium is replaced by a liquid medium (Understand level) In-class Compare the… Q. EXPERIMENT 8 To Determine the Wavelength of Sodium Light using Newton’s Rings Please read additional instructions on the bench for setting up the PC and camera for this experiment Introduction Newton’s rings are interference fringes of equal thickness which are produced in the air ﬁlm be-tween a convex surface and an optical ﬂat. NEWTON'S RINGS are the circular interference pattern first discovered by Newton. Ans. 11. Formation of fringes When a plano-convex lens with large radius of curvature is placed on a plane glass plate such that its curved surface faces the glass plate, a wedge air film (of gradually increasing thickness) is formed between the lens and the glass plate. Newton's rings is an interference pattern caused by the reflection of light between two surfaces - a spherical surface and an adjacent flat surface. The interference is between the reflexions from twoneighboring surfaces; 2. The experiment is performed when there is an air film between the plano-convex lens and the optically plane glass plate The diametre of the mth and the (m+p)th dark rings are determined with the help of a travelling microscope. newton’s rings - q15 15) On which factors does the diameter of a ring depend? Newton’s Rings and Determination of the Wavelength of Light Newton’s Rings. Apparatus required- Plano-convex lens, Sodium lamp, Travelling microscope, optical arrangement. These are known as Newton’s ring. Newton’s Rings Experiment Aim: To determine the wavelength of monochromatic light (sodium light) using 10. If the waves that enter the lens are of arbitrary phase, and of all possible wavelengths Newton's rings in transmitted and reflected white light . Formula used – The wavelength of light is given by the formula = 2 + −2 4 Where Dn+p – Diameter of (n+p)th ring. Newton’s Rings 38 Discussion (i) The Newton’s ring experiment can be also used to find the wavelength of a monochromatic light. When a plano-convex surface is placed on a glass plate, an air film of gradually increasing thickness is formed between the two and monochromatic light is allowed to fall normally on film and viewed in reflected light, alternate dark and bright rings are observed. Newton's Second Law of Motion deals with unbalanced forces; the acceleration of an object is related to the mass of the object and the force applied to it, or F=ma. View Newton's ring.pdf from MATH 111 at Pandit Deendayal Petroleum University. Formula used: The wavelength of light is … How are these rings formed? Apparatus used: A Plano convex lens of large radius of curvature, optical arrangement for Newton’s rings, plane glass plate, sodium vapour lamp and traveling microscope. Two salient reasons: 1. As shown in figure arrange the lens with glass plate. Learning Objectives for In-class and Out of class Out of class At the end of watching the videos student should be able to, Define the interference pattern formed in Newton’s rings experiment (Recall Level).