Refractive index measurements to compare chemical purity refractive index, n, is a measure of how fast light travels through a substance. Refractometry is a technique that measures how light is refracted when it passes through a given substance, in this case, an unknown compound. As light passes through the interface between two mediums of different refractive indices, it bends as shown in fig. Refractive index of material of a prism experiment. The refractive index also depends on the wavelength colour of the light ray. Check that the cooling water is flowing and record the water temperature on the precision thermometer to 0.
Study of concentration dependence of refractive index of. Youll get the best results with a clear, glass container for this experiment. Refractive index of different liquids using hollow prism. This could be because a misjudgement when finding the point of.
The equation is valid for visible radiations and normal atmospheric conditions. To determine refractive index of a glass slab using a travelling microscope. Abbes refractometer, temperature controller, light source and samples. Refraction and interference with microwaves 3 figure 1 waves incident on an interface between index of refraction n 1 and n 2. Since the index of refraction depends on both the temperature of the sample and the wavelength of light used these are both indicated when reporting the refractive index.
The refractive indices measured with mirrors that had longer focal lengths were more accurate than mirrors with short focal lengths. Physics lab report refractive index sine refraction. Experiment 26 reflection and refraction advanced reading. Determination of the refractive index of a liquid using the apparent depth method pack contents. Refractive index lab worksheet example answers pdf.
Water is the most abundant compound on earths surface. A simple method to measure the refractive index lee white. Determination of the refractive index of a glass block using law target group. The refractive index n of a transparent material can be determined by measuring the angle of incidenc e and the. If i is the angle of incidence of a ray in vacuum angle between the incoming ray and the perpendicular to the surface of a medium, called the normal and r is the angle of refraction angle between the ray in. Diploma in basic education students also suitable for.
The experiment produced a refractive index close to that of water, excluding the flexible mirror. The refractive index n can also be defined for a particular material as the ratio of the speed of light in. Introduction the refractive index of air affects the wavelengths of electromagnetic radiations through the relation. Experiment aim to determine refractive index of a glass slab using a travelling microscope. Concluding the refractive index of the glass block n glass was found from the graph of sin i plotted against sin r from experiment to be 1. Determination of the refractive index of a liquid using. Assessment of refractive index of pigments by gaussian fitting of light backscattering data in context of the liquid immersion method article pdf available in applied spectroscopy 645. In this paper the main properties of a prism of initially unknown refractive index and material will be analysed. The refractive index is an important optical parame. To study concentration dependence of refractive index of sugar solution and salt solution 1.
Refractive index lab worksheet example answers pdf teach. The experiment would be suitable in the undergraduate physics laboratory. The equation showing the slope corresponds to the refractive index of the liquid. An experimental method for determination of the refractive index of. The aim of the experiment is to study the refraction index of a glass. The experiment was considered to be precise as the uncertainty of nglass is quite small, and accurate since after the uncertainties of 0. The higher the sugar concentration, the more light bends higher refractive index. According to our measurements, value of refractive index of water is 1. Jan 07, 2016 for the love of physics walter lewin may 16, 2011 duration. Is defined as the ratio of velocity of light in vacuum to the velocity of light in a substance at same wave length. Figure shows the angle of incidence on an air water boundary.
Determination of the refractive index of the material of a prism using sprectometer debangshu mukherjee b. Measuring the refractive index of a liquid 1 turn on the light. The object of this experiment is to study the laws of reflection and refraction. Measuring the refractive index understanding standards. This property is very helpful in designing optical lenses as it allows to calculate the bend angle of beam of light when passes. If i is the angle of incidence of a ray in vacuum angle between the incoming ray and the perpendicular to the surface of a medium, called the normal and r is the angle of refraction angle between the ray in the medium and the normal, the refractive index n. Pdf assessment of refractive index of pigments by gaussian. Therefore total absolute uncertainty for the refractive index. In this experiment, you are required to the refractive index of an acrylic determine trapezoid or any block with parallel faces by using snells law. Phy pack 4 refractive index law 2 produced by physics group, university of cape coast, as part of a delphe funded project title. A refractometer measures the extent to which light is bent i. A student uses a glass block to determine the refractive index using the real and apparent depth method and obtained a value of 1. To find refractive index of the given liquid samples and find molar refraction and specific refraction. Easy to use operation consists of placing a sample on the prism.
Place the plexiglass triangle on a sheet of paper and trace around the edges. Pdf the present experiment discusses, presumably the most basic method, for determination of refractive index of optically transparent. Clean the prism face with acetone and carefully blot it dry with a kimwipe. As the given value for the refractive index of water is 1. There is a minimum numerical value for the refractive index of a liquid substance.
We used a mason jar since all of our drinking glasses have an etched design in them. Determination of the refractive index of water using a concave mirror method 1. Because the refractive index of a vacuum is defined as 1. A simple method to measure the refractive index lee white and. The refractive index is a dimensionless parameter that helps us in our estimation or determination of the degree of bending for a ray of light entering one medium from another. Apparatus and material required a travelling microscope, a glass slab, lycopodium powderchalk dust and a paper. Pdf determination of refractive index of optically transparent.
Refractive index refraction of light higher physics. We will explore two different types of distillation. This theoretical formulation entails a positive change of refractive index upon ideal mixing, which is interpreted in terms of dissimilar london. The refractive index of thermodynamically ideal liquid mixtures is demonstrated to be given by the volume. Refraction is due to the change in speed of light while. Theory and experiment an innovative approach is presented to interpret the refractive index of binary liquid mixtures. Students determine the refractive index of a liquid with a simple technique using a semicircular hollow block. The mirror with the longest focal length, 30 cm, gave the refractive index to be 1. The experiment could be turned into a class activity for measuring the refractive index of water. Refractive index database about shelf main simple inorganic materials organic organic materials glass glasses other miscellaneous materials 3d selected data for 3d artists.
In section 2 we describe the optofluidic lens fabrication method. The refractive index of a substance is ordinarily determined by measuring the change in direction of colliminated radiation as it passes from one medium to another. The amount by which the light is refracted determines the refractive index. Since it is necessary to use a computer program when determining the refractive index, students could be given the opportunity of.
Refractive index of different liquids using hollow prism 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. Then they predict the refractive index of a material a pyrex glass tube by matching it with the known refractive index of a liquid using the percent light transmission measurement. Refractive index of material of a prism experiment edunovus online smart practicals. The homemade light intensity detector uses an led and multimeter, which are relatively inexpensive. Determination of the refractive index of a glass block using.
For the love of physics walter lewin may 16, 2011 duration. Final value of refractive index of water relative to air. The refractive index is a unitless number, between 1. As shown in figure arrange the lens with glass plate. The closer the refractive index is to the literature values, the purer the sample. The transmitted light ray has small deviation of the path from the incident angle. Determination of the refractive index of a liquid using the. This is described by snells law of refraction, n 1 sin. No, the refractive index of the glass will not change because it is the same material. Hold the tip of the pencil while inserting it into the water. Measureing refractive index values with use of polarizer 1.
The resolution of the refractometer increases with projection distance. The higher the refractive index of a medium, the lower will be the speed of light passing through it. Section 3 mentions the liquids used in the experiment. The refractive index determines how much the path of light is bent, or refracted, when entering a material. The refractive index of a material is a measure of the change in the speed of light as it passes from a vacuum or air as an approximation into the material. Refractive index can be used to identify an unknown liquid compound, or it can be used as a means of measuring the purity of a. Refractive index a refractometer measures the extent to which light is bent i. The experiment is performed when there is an air film between the planoconvex lens and the optically plane glass plate. Refractive index is defined as the ratio of the velocity of light in air to the velocity of light in the medium being measured. Sc physics,1st year chennai mathematical institute 17. This quantity, usually labeled n, is simply the factor by which an electromagnetic wave is slowed upon entering a material medium from a vacuum region. Refraction, law, realapparent depth method, geometric optics. Refractive index of material of a prism experiment edunovus.
Refractive index, also called index of refraction, measure of the bending of a ray of light when passing from one medium into another. Refractive index or the index of refraction is the ratio of the speed of light in vacuum or air to the speed of light in a transparent material. A medium with a higher refractive index is an optically denser medium. Determination of the refractive index of a glass block. The refractive index of the prism has to be higher than that of the medium under measurement, as otherwise there will be no total internal reflection. Refractive index of material of a prism experiment edunovus online smart practicals duration. If c is the velocity of light in free space, the time taken by light to travel a distance of x in a medium of refractive index is. Refractometer refractive index at thomas scientific. Activitylab worksheet example answers 1 determining the refractive index of water. The measuring prism acts as the refractive index reference. The value does not diverge much from values listed in tables, that is 1. Liquid refractive index measurement system based on.
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