Physics practical 6 newtons ring february 23, 2018 method. Newtons ringsformation of newtons ringsthin filmradius. Newtons ring experiment viva concepts apni physics. At the point of contact of the lens and the glass plate, the thickness of the film is effectively zero but due to reflection at the lower surface of air film from denser medium, an additional path of. Notes, exercises, videos, tests and things to remember on newtons rings and determination of the wavelength of light. A monochromatic source of light s is kept at the focus of a condensing lens l 1. Above equation is used to nd the wavelength of monochromatic light using newton ring s method, in which material of refractive index is immersed between planoconvex. Series and parallel lcr circuits determination of resonant frequency and quality factor 3. The distances between the interference rings are not constant as the convex boundary is curved. Pdf under graduate physics laboratory manual for ph1005. Experiments in engineering physics bachelor of engineering and technology prepared by, p. Newton observed these rings when placing a spherically shaped piece of glass a lens touching a flat piece of glass. Engineering physics experiments viva questions with answers.
Experiments in engineering physics physics lab manual fourth revised edition. Physics viva for 2nd year 1 what is a spectrometer. The central ring should be dark throughout the experiment. Pdf this laboratory manual provides the theory of the experiments, the. They are formed as a result of interference between light waves reflected from the upper and lower surfaces of the. When a light ray is incident on the upper surface of the lens, it is reflected as well as refracted. The movement is stopped when it reaches at the 22 nd dark ring. When the two or more waves superimpose over each other, resultant intensity is modified. It is named after isaac newton, who investigated the effect in his 1704 treatise opticks.
To determine the wavelength of sodium light using plane diffraction grating 39 selfstudy experiment 43 appendix 47 questions for examination 60 scheme of experiments. Newtons rings experiment is a classic example of fringes of equal thickness or fizeau fringes 1,2. Aim to determine wavelength of sodium light using newtons rings. To determine the radius of curvature of a plano convex lens using newtons rings methods 36 8. If by chance, you get a bright central spot in your experiment, will you proceed with the experiment with the same system of fringes or will you reject. Jun 02, 2011 these concentric rings are known as newtons rings. A pure semiconductor completely free from impurities is called intrinsic semiconductor. Apparatus required newtons rings apparatus, travelling microscope, sodium lamp, a convex lens and a spherometer. If by chance, you get a bright central spot in your experiment, will you. Newton s rings can be explained on the basis of wave theory of. What happens when convex lens in newton s ring experiment is. Identification of unknown passive electrical components and determine the value of inductance and capacitance 2. When a plano convex lens of long focal length is placed over an optically plane glass plate, a thin air film with varying thickness is enclosed between them.
These are some additional questions may be asked during vivavoce as well as. A plano convex lens of large radius of curvature, optical arrangement for newton s rings, plane. In the traditional version of newton s rings, a slightly convex lens is placed above a flat glass plate or optical flat. To determine the radius of curvature of a plano convex lens using newtons rings methods 36. Determination of the wavelength of a monochromatic source by using newtons ring experiment. Introduction newtons ring is the demonstration of the interference of light waves reflected from the surface of a thin air film formed between the plane glass and the convex lens whose. To observe newton rings formed by the interface of produced by a thin air film and determine the radius of curvature of a planoconvex lens.
Because the plano convex lens and the plane lens both are in contact and at that particular place the centre dark ring will appear. A plano convex lens of large radius of curvature, optical arrangement for newtons rings, plane glass plate, sodium vapour lamp and traveling microscope. In this case, the radius of curvature of the convex surface of the given lens is supplied or is determined otherwise. What happens when convex lens in newtons ring experiment is replaced by a concave lens of varying refractive index. By employing sodium light whose mean wavelength is 5893a, r can. A thin air film is formed between the plate and the lens. To form newtons rings and then find the radius of curvature of a. What is the basic principle of newtons rings experiment. The interference is between the reflexions from twoneighboring surfaces. Typical newtons rings as observed in physics laboratory of sgsits, indore. Newtons rings is a phenomenon in which an interference pattern is created by the reflection of light between two surfaces. What will happen if we use white light in newtons ring. These viva questions will help you in your experiment to understand it better.
In transmitted light the ring system is exactly complementary to the reflected ring system so that the centre spot is bright. It is a substance with conduction properties between metals and insulators. If the radius of curvature of the lens is 100 cm, find the wave length of the light. May 06, 2018 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. Because the experiment is usually done with a flat mirror, and a spherical lens. Newtons rings are a fun demonstration of the wave nature of light, and also of the fact that white light is made up of many components of different wavelengths. The newtons rings we see are formed by transmitted light or refracted light. From this the diameter of the ring is found out which is the difference between the readings on the left and right sides. Dec 20, 20 the interference rings can be observed both in reflection and in transmitted light. Newtons rings are nothing but concentric circular alternate bright and dark interference fringes, formed due to superimposition of light beams. Oct 22, 2007 newton s rings are a fun demonstration of the wave nature of light, and also of the fact that white light is made up of many components of different wavelengths. What type of air film do you get when thin plate is placed between two plane parallel glass plates. Questions related to newtons ring experiment yahoo. When viewed with white light, the fringes are coloured shown in the wrapper of the text book.
Newton s rings is a phenomenon in which an interference pattern is created by the reflection of light between two surfaces. What is the value of z in lcr series circuit at resonance. The key idea behind newtons ring experiment is the thin film formation between a planeconvex lens and a glass plate. In a newtons rings experiment the diameter of the 15 th ring was found to be 0. Zener diode experiment viva questions with answers characteristics mcqs interview questions. The interference rings can be observed both in reflection and in transmitted light.
If the waves that enter the lens are of arbitrary phase, and of all possible wavelengths newtons rings in transmitted and reflected white light. Nov 04, 2014 newtons rings newtons rings are nothing but concentric circular alternate bright and dark interference fringes, formed due to superimposition of light beams reflected from a thin air. To find the wavelength of sodium light by newton s ring. The frequency of applied ac at which resonance takes place or current is maximum. In this case, the radius of curvature of the convex surface of. To determine the wavelength of sodium light by newtons ring method.
Consequently, the center of newton rings is dark due to destructive. To determine wavelength of sodium light using newtons rings. The simulation virtualizes the newtons rings experiment. The pattern was first observed by sir isaac newton. An air film of varying thickness is formed between the lens and the glass sheet. Newtons rings can be explained on the basis of wave theory of. The newtons rings experiment is set up as shown in fig. Newtons rings newtons rings are nothing but concentric circular alternate bright and dark interference fringes, formed due to superimposition of light beams reflected from a thin air. Laboratory manual for newtons ring method background coherent sources of light, concept of interference, interference by division of wave front and amplitude, interference in thin lms, newtons ring apparatus. Questions related to newtons ring experiment 1 what will happen if the planoconvex lens is moved upward from the glass plate by a distance of. A plano convex lens of large radius of curvature, optical arrangement for newtons rings, plane. Newtons rings and determination of the wavelength of light.
The experimental setup used for the experiment is shown in g. An important application of interference in thin films is the formation of newtons rings. Determination of wavelenght of sodium light using newton. In order to determine the refractive index of liquid the newtons ring experiment is first performed for the air medium. Monochromatic light is used to illuminate the lenses. Graph of ring no versus diametersquare to determine the average. Before starting the experiment, the glass plates and plano convex lens should be. To find the wavelength of sodium light by newtons ring. Applications of newtons ring engineering physics class. The rings are caused by interference of light waves. Traveling microscope, sodium vapour lamp, planoconvex lens, plane glass plate, magnifying lens. The wavelength of monochromatic light can be determined as. Laboratory manual for newtons ring method background coherent sources of light, concept of interference, interference by division of wave front and amplitude, interference in thin lms, newtons.
The voltage at which the zener diode breaks down is called the zener voltage. Typical newtons rings as observed in physics laboratory of. They are formed as a result of interference between light waves reflected from the upper and lower surfaces of the air film developed between the convex surface of plano convex lens and plane glass plate. To determine the wavelength of sodium light using newtons. Newtons ring experiment viva questions are listed here. To determine the wavelength of sodium light using newtons rings table 8. The mercury vapour highpressure lamp with the double condensator focal length 60 mm fitted, the lens holder with the interference filter, the newtons rings apparatus, the lens holder with the lens of focal length 50 mm and a transparent. When viewed with monochromatic light, newtons rings appear as a series of concentric, alternating bright and dark rings.
Newtons rings 38 discussion i the newtons ring experiment can be also used to find the wavelength of a monochromatic light. Newtons ring is the phenomenon in which because of the reflection of light with the two surfaces, i. What do you mean by resolving power of a telescope. Whenever light travels from a medium of one refractive index to another medium of different refractive index, a fraction of incident light gets reflected and this is given mathematically by fresnels equations. Newtons rings and determination of the wavelength of light found mistakes report here. They are observed when light is reflected from a planoconvex lens of a long focal length placed in contact with a plane glass plate. Thin film interference with films of varying thickness newtons rings. Video of a simple experiment with two lenses, and newtons rings on mica observed. Zener diode is a pn junction diode specially designed for operation in the breakdown region in reverse bias condition. The experimental setup used for the experiment is shown in fig. Determination of the width of a paper employing wedge interference phenomenonaim. Sample data table ring number lm j lm l1j rm j rm r1j dm 24 23 22 1 spherometer a spherometer is used to. Newtons rings, in optics, a series of concentric light and darkcoloured bands observed between two pieces of glass when one is convex and rests on its convex side on another piece having a flat surface.
Diagram for formation of newtons rings through the transmission of light. Newtons rings is a phenomenon in which an interference pattern is created by the reflection of. In this video i shared some viva questions for newton s ring experiment which are commonly asked in viva. Alternate dark and bright rings formed due to presence of air film when plano convex lens is placed on glass plate is called newtons rings. The modification in the distribution of intensity in the region of superposition. Under graduate physics laboratory manual for ph1005 sgsits physics laboratory. What are the precautions to be taken care of and what are the. Newtons strings are viewed through the eyepiece of the travelling. Isaac newton was the to first study the newtons ring pattern in 1717, so it was named as newtons rings. To determine the radius of curvature of a given lens by forming newtons rings.
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