How newton''s ring can be obtained in the laboratory, Physics

Q. Explain how Newton's ring can be obtained in the laboratory. Why Newton's rings are circular in shape? How the Newton's rings are used to find refractive index of liquid?

Ans. When a Plano-convex lens of large radius of curvature is placed on a glass plate with its convex surface, a thin air film of gradually increasing thickness is formed between the upper surface of glass plate and the lower surface of the Plano convex lens. When this system is viewed in reflected monochromatic light, then alternate bright and dark concentric rings with their dark centre and formed. These fringes are circular in shape because the air film is symmetrical about the point of contact of lens with the plane glass plate. These rings are known as Newton's rings.

These rings are formed because of the interference between the wave reflected from top and bottom surface of an air film formed between the lens and glass plate.

S is broad source of monochromatic light placed at the focus of lens L1. The light rays emitted from source S are made parallel by lens L1. These emitted light rays are incident on glass plate G1 inclined at 45°, rays and rays reflected from this plate falls normally on the system. (Convex lens and plate). Interference occurs between the rays reflected from upper and lower surface of the film. The interference fringes are viewed by a microscope.

Measurement of Refractive Index -

Hence refractive index µ can be determine by measuring the diameter of Newton's rings first with air and then with the liquid for same value of m.



Posted Date: 7/12/2012 7:16:00 AM | Location : United States

Related Discussions:- How newton''s ring can be obtained in the laboratory, Assignment Help, Ask Question on How newton''s ring can be obtained in the laboratory, Get Answer, Expert's Help, How newton''s ring can be obtained in the laboratory Discussions

Write discussion on How newton''s ring can be obtained in the laboratory
Your posts are moderated
Related Questions
two balls connected by massless string wherein the first ball A is confined to a plane surface with frection and the second ball B, due to the string’s passage through a small hol

Violet light (λ = 415 nm) falls on a slit that is 0.040 mm wide. The distance among the centers of the central bright band and the third-order dark band is 18.7 cm. What is

Are fiber optics systems difficult to install? This becomes significant to establish a fair comparison with other components, in this case normal light fixtures. Fiber optics s

Define Ideal Gas in One-Dimensional Potential? An ideal gas of particles, each of mass m at temperature ?? is subjected to an external force whose potential energy has the f

Is there any other proof that light is an electromagnetic wave other than its speed has the same value as the inverse square root of the permittivity and permeability constants of

Q. Situation of the converging lens - Principle Ray 1? Principle Ray I . The easy one just as in the case of the converging lens this ray goes straight through the centre of t

Write the expetiment of vernier caliper?

An experiment with force and motion Tie a spring clothes peg open by placing one winding of thread about the long ends. Place the clothes peg in the centre of a long table and

A plane diffraction grating of width 2.5cm has 1500 rulings. Monochromatic light of wave length 5893A 0 is incident normally on it. Determine the angle at which second order princ

How i make a goood physics project for my University Assignment?