The speed of light in a given substance is v cn, where n is the index of refraction of the substance. To study refraction of light in rectangular glass slab physics kids projects, physics science fair project, pyhsical science, astrology, planets solar experiments for kids and also organics physics science ideas for cbse, icse, gcse, middleschool, elementary school for 5th, 6th, 7th, 8th, 9th and high school students. Looking at a straight object, such as a pencil in the figure here, which is placed at a slant, partially in the water, the object appears to bend at the waters surface. A slab is a piece of transparent material with rectangular faces. Measure the angle of incidence, angle of refraction. This video is highly rated by class 10 students and has been viewed 920 times. Consider a rectangular glass slab, as shown in figure. For a slab of infinitesimal thicknessdx and temperature differencedt, we can. Cbse class 10 science chapter 10 light reflection and. Class 10 science chapter 10 light reflection and refraction. Mar 27, 2017 when a beam of light fall in the glass slab it get refract twice one from air to glass and another glass to air, and their imaginary rey and refracted rey looks like parallel this shifting of ray is called lateralshiftwhereas in glass prism, whe. Dec 03, 2016 to observe refraction and lateral deviation of a beam of light incident obliquely on a glass slab.
Refraction through a glass slab and the refractive index. To register science tuitions on to clear your doubts. Refraction of light part i this laboratory was designed to investigate the behaviour of light as it travels through a less dense into a denser medium. On entering the glass slab, it bends towards normal and travels along ef at an angle of refraction r. Refraction of light when it passes from one medium to the other obeys snells law, which states. Snells law gives the relationship between angles of incidence and angle of refraction. There is a change of the medium in this case twice.
When light falls on a highly polished surface like a mirror most of the light is sent back into the same medium. Lateral shift when a ray of light is incident obliquely on a parallel sided glass slab the emergent ray shifts laterally. Refraction through a glass slab and the refractive index slideshare. A ray ae is incident on the face pq at an angle of incidence i. Explain refraction of light through a glass slab a plus. Let us consider that light enters from medium 1 to medium 2.
Measure the angle of incidence, angle of refraction, angle of emergence and interpret the result. Thus the refracted ray bends towards the normal making r sep 09, 2018 refraction through a rectangular glass slab and principle of reversibility of light. Describe what happens to a ray of light when it passes from air through a denser medium and into air again cs1 answer. The light may be reflected back from the surface, transmitted through the material in which case it will deviate from its initial direction, a process known as refraction or absorbed by the material if it is not transparent at the. Refraction through a rectangular glass slab and principle of reversibility of light. Jan 17, 2020 ncert class 10 science lab manual refraction through glass slab. Jan 12, 2015 let us consider a light ray passing through a glass slab of certain thickness t. From te analysis from phase matching from fermats principle of least time total internal reflection and fibers fios. Here in this figure ao is the light ray traveling in air and incident on glass slab at point o. Why do i sometimes see my reflection in a glass slab. Fix a sheet of white paper on a drawing board with drawing pins. We have learned that refraction occurs as light passes across the boundary between two media. Tracing the path of a ray of light passing through a rectangular.
Normal shift and lateral shift due to refraction of light. Pdf determination of refractive index of optically transparent. Mar 04, 2012 dispersion occurs when light is passed through a prism. Powered by create your own unique website with customizable templates. Look through the glass slab along the plane of the paper from the side sr and move your head until the images of the two pins a and b are seen clearly. All faces are transparent and opposite faces are parallel. Applications of refraction of light physics special. To study refraction of light in rectangular glass slab. Determination of the refractive index of a glass block. Mar 24, 2009 well refraction does occur in a glass slab the primary difference is that a glass slab has parallael surfaces while prism has 3 non parallel onesthe point is that when we draw the ray diagram for a ray that passes through a glass slab,we usuall draw for 1 ray but the point is that a beam of rays strike the glass slab and effective overlapping occurs in the emergent rays that. Dec 02, 2016 to determine refractive index of a glass slab using a travelling microscope. It is defined as, where c is the speed of light in vacuum and v is the phase velocity of light in the medium. Well, in fact, dispersion does occur when light is passed through a glass slab it is just harder to observe that way. C is the velocity of light and v is the velocity of light in that medium.
Let us consider a light ray passing through a glass slab of certain thickness t. Refraction of light through a glass block when a ray of light enters a glass block at an angle other than the normal, it changes speed, wavelength and direction as shown below. We can also sometimes see our reflection even if we look to the mirror with perpendicular angles of incidence. Refraction through glass slab a ray of light incident on one of the parallel faces of a rectangular glass slab, emerges out of the opposite parallel face gets absorbed into the body of the. Refraction occurs when light goes through a water surface since water has a refractive index of 1. The perpendicular distance between the direction of the incident ray and emergent ray is called lateral shift. Why does dispersion take place when light is passed. Sep 17, 2017 refraction of light through glass slab duration. Refraction is also responsible for rainbows and for the splitting of white light into a rainbowspectrum as it passes through a glass prism. How is refraction from a glass slab different than the.
Class 10 physics practical glass slab introduction. When a ray of light passes through a rectangular glass slab, it gets bent twice at the air glass interface and at the glass air interface. Light is refracted by the glass slab is very much responsible for this fact. The incident ray and the emergent ray in the air are parallel. Ace your next assignment with help from a professional writer. Again when it is moving away from the glass slab into the air it moves towards the normal. Three glass slabs of different thickness but same material, a travelling microscope, lycopodium powder. This means that i r the angle i is greater than the angle r. In the case of a glass slab, the opposite sides are parallel and therefore different colors emerge. Place the given glass slab nearly in the middle of the sheet. Snells law where and are the angles from the normal of the incident and refracted waves, respectively. Snells law describing refraction was first recorded by ptolemy in 140 a. Thus the refracted ray bends towards the normal making r of the slab, the ray ef while travelling through glass meets the surface sr of air which is a rarer medium. To determine refractive index of a glass slab using a.
The emergent ray is parallel to the incident ray and is displaced through a distance. Departing space station commander provides tour of orbital laboratory duration. Measure the angle of incidence, angle of refraction, angle of. A ray of light traveling in water is incident on its surface open to. When light travels through something else, such as glass, diamond, or plastic, it travels at a different speed. A lens uses refraction to form an image of an object for various purposes, such as magnification. Why does dispersion take place when light is passed through.
It means that light is travelling from a rarer medium i. To trace the path of a ray of light passing through a rectangular glass slab for different angles of incidence. Draw accurately the outline of the rectangular glass block. For example white light, after passing through a slab of coloured glass, will emerge from the other side with a different mixture of frequencies, i. Refraction has many applications in optics and technology. Typical values for the index of refraction of glass are between 1. Dispersion occurs when light is passed through a prism.
If the light starts outside the slab with an angle less than 90 degrees, the light inside the slab will have an angle less than the critical angle and some light will come all the way through to the other side. Determination of the refractive index of a glass block using. Consider that a ray of light enters the glass slab along ae. Refraction and snells law reading shen and kong ch. The speed of light in glass or water is less than the speed of light in a vacuum or air. Sep 23, 2019 chapter 10 class 10 light reflection and refraction. Refraction through a rectangular glass slab youtube. Ncert class 10 science lab manual refraction through glass slab.
The dispersion is caused due to the the difference in the angle of deviation for different colours. Nov 17, 2015 consider that a ray of light enters the glass slab along ae. On entering the glass slab, it bends towards normal and travels along ef. Explain refraction of light through a glass slab a plus topper. In the case of a glass slab, the opposite sides are parallel and therefore different colors emerge parallel to each other and are seen simultaneously. This also happens in a lens in going from a less dens e medium air to a more dense medium glass, light bends towards the normal. Closing your one eye,adjust the position of your head in such a way that the images of the pins a and b lie in the same straight line.
Snells law and the refraction of light the displacement of light by a slab of material when a ray of light passes through a pane of glass that has parallel surfaces and is surrounded by air, the emergent ray is parallel to the incident ray. Outline te and tm fields refraction and snells law. Depending on the type of spherical lens used convex or concave refraction through glass has many uses. Reflection and refraction when light hits a surface, one or more of three things may happen. Fasten a sheet of paper to a drawing board or flat surface into which pins can be pressed easily. When a ray of light pq incident on the face ab of glass slab, then it bends towards the normal since refraction takes place from rarer to denser medium. The light may be reflected back from the surface, transmitted through the material in which case it will deviate from its initial direction, a process known as refraction or absorbed by the material if. Ncert class 10 science lab manual refraction through glass. When light travels from one medium to another, it generally bends,this bending is called refraction. When the light ray is entering from a into the glass slab it moves towards the normal. D first described by relationship by snellius in 1621 first explained in 1650 by fermats principle of least time. When a collimated beam of white light enters a rectangular prism, it develops slightly coloured edges due to the dispersive refraction of the glass. To trace the course of different rays of light through a rectangular glass slab at different angles of incidence, measure the angle of incidence, refraction and.
To understand the refraction of light through a glass slab consider the figure given below which shows the refraction of light through a rectangular glass slab. When a beam of white light passes from air into a material having an index of refraction that varies with frequency, a phenomenon known as dispersion occurs, in which different coloured components. In optics, the refractive index or index of refraction of a material is a dimensionless number that describes how fast light travels through the material. To observe refraction and lateral deviation of a beam of. Refraction through glass slab a refraction through a rectangular glass slab and principle of reversibility of light. Icse solutions for class 10 physics refraction of light a. Light laws of refraction the incident ray, the refracted ray and the normal at the point of incidence all lie in the same plane. Light refraction of light complete these ray diagrams. Glass slab, drawing board, white paper sheet, drawing pins, office pins, protractor. Gcse physics refraction of light through a glass block.
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