Determining the refractive index of a liquid chm 220. To do this i am using a light ray box to shine a ray onto a rectangular perspex prism, and then using. The aim of this experiment is to calculate the refractive index of the material of a glass prism. Spectrometer, prism, prism clamp, sodium vapour lamp, lens. An experimental method for determination of the refractive. Clean the prism face with acetone and carefully blot it dry with a kimwipe. In part 1 of this lab you will investigate the bending of light as it travels from.
In most applications, the index of refraction of air can be taken to be one, with negligible. 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. What is the connection between the refractive index of a. For manual work, the doflimits are usually indicated on the. Using a penlight or flashlight, predict and investigate how a variety of objects and materials affect the transmission of light. Spectrometer, refractive index of the material of a prism. Refractive index of two fluids when mixed physics forums. The refractive index between any two media is a constant and is given the symbol the second law of refraction is also known as snells law. Check that the cooling water is flowing and record the water temperature on the precision thermometer to 0.
Measuring the refractive index understanding standards. Refractive index of the material of the prism is determined by using equation3 result. If you place a drinking straw into a glass of water, the star will appear bent. Refractive index between two media, 1n2 is a ratio of the speed of light in material 1 to that in material 2 1 we can assume n at an airsubstance boundary is the absolute n of a substance. The refractive index of a medium is the ratio of the sine of the angle of incidence to the sine of the angle of refraction when light travels from a vacuum into that medium. A refractometer is a device that will measure the degree to. Refractive index determinationusing the central focal masking. Pdf determination of refractive index of optically transparent. When a laser beam impinges obliquely on a rectangular cell filled with liquid and passes through the cell, the propagation axis of the transmitted beam is displaced from that of the incident beam. Equation 2 can be used to nd a relationship between the angle of the incident wave, still measured with respect to the normal, and the angle of the light ray as it moves through this second material, known as the angle of refraction. What fraction of the initial intensity is reflected.
Object prediction results absorbed, reflected, refracted. Refraction and interference with microwaves 4 question 4. Activitylab worksheet example answers 1 determining the refractive index of water. Refractive index is one of the most important optical properties of a medium. Refractive index of glass and its dispersion for visible light.
Homework statement my question is very basic, yet one which has become increasingly frustrating. Therefore total absolute uncertainty for the refractive index. Sample problems for the index of refraction important information your reading introduced you to the concept of index of refraction, n, defined by n cv, where c 2. Measuring the refractive index of a liquid 1 turn on the light. Optical constants of water in the 200nm to 200m wavelength region, appl. Review scientific inquiry before creating the following experiment. Traditionally, these quantities are summarized within the framework of empirical relations 1, 4, 78 that are suitable for lens design, but give little insight into processes determining the index. Refractive index a refractometer measures the extent to which light is bent i. The aim of the experiment is to study the refraction index of a glass. To determine the refractive index and dispersive power of prism material by spectrometer.
Refractive index determinationusing the central focal. The higher the refractive index the slower the speed of light in that medium. Would you end up with the same refractive index as the both solutions or will the refractive index change. By measuring the displacement, we can determine the refractive index of the liquid. It plays vital role in many areas of material science with special reference to thin film technology and fiber optics. The refractive index determines how much the path of light is bent, or refracted, when entering a material.
To find refractive index of the given liquid samples and find molar refraction and specific refraction. The speed of light in an unknown medium is measured to be 2. To measure the refractive index of a liquid lawless. Feb, 2015 how to determine the refractive index of a block. May 05, 20 i was wondering what will happen if you have two aqueous solutions with the same refractive index and you mix them. We see linear dependence of concentration with refractive index from the graph above.
Combined theoretical and experimental study of refractive indices. Optofluidic systems combine the compactness and portability of. Study of concentration dependence of refractive index of. However, in the light of the agreement of our results with those found in literature, we argue that the measured value of the refractive index of the used benzene is acceptable. Using a particular monochromatic light source, the apparatus is calibrated with water as the liquid. Please refer laboratory manual class xi ncert experiment3. Now combine all your data to make a single table of. 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. The refractive index n of an optical medium is defined as the ratio of the speed of light in. Determination of the refractive index of a liquid using. Spectrometer, prism, mercury vapour lamp, spirit level and reading lens.
A simple method to measure the refractive index lee white. Pdf the present experiment discusses, presumably the most basic. Concentration in most solutions, the concentration of solute in a solvent can be determined by measuring the refractive index n d. Data csv comma separated txt tab separated full database record. For a given color, the refractive index of a medium depends on the density of the medium.
Refractive index distribution of single cell and bacterium. Index of refraction is measured without embedded tracers using a refractometer atago inc. Refractive index lab worksheet example answers pdf. Controlled variables in exp to determine refractive index.
To determine refractive index of a glass slab using a travelling. Abbes refractometer, temperature controller, light source and samples. Descartes, in 1637, performed this experiment of passing rays of light through a large. The refractive index of glass is a function of the wavelength of light, a property known as. The refractive index of a material is one of the most important optical parameters. For the deionized water with which the particles are manufactured, the refractive index is 1. If the distance of the pointer from the top of the lens is 23. Bioprocessing tutorial concentration measurement with. As the given value for the refractive index of water is 1.
Hold a plane mirror so that its back is level with the water. The refractive index n of an optical medium is defined as the ratio of the speed of light in vacuum. Determination of refractive index of transparent liquids using the first. In contrast, a less dense, lower refractive index material will reflect light in phase. Refraction and interference with microwaves 3 figure 1 waves incident on an interface between index of refraction n 1 and n 2. The experiment could be turned into a class activity for measuring the refractive index of water. Get the ray e by joining the two terminal points of rays b and c at interfaces. Determination of the refractive index of a glass block. The method we used in the experiment to measure the refractive index of sugar solution and salt solution consists of intense monochromatic source of light, laser. Determine the slope, which is your average refractive index. If the medium has a complex refractive index you would have to take it into account as in maccos answer. Place the prism on the turntable of the spectrometer and adjust its position until the laser beam runs parallel to, and just grazes, one of the sides of the prism. This comparison is used to help confirm the identity of the compound andor assess its purity.
The refractive index n of a transparent material can be determined by measuring the angle of incidence and the angle of refraction as a ray of light enters, or leaves the material. From my understanding, refractive index is an indication as to how the speed of light changes when it passes through a material. Traceable standards for improved data security density. The refractive index also depends on the wavelength colour of the light ray. The equation showing the slope corresponds to the refractive index of the liquid.
Feb 16, 2010 homework statement my question is very basic, yet one which has become increasingly frustrating. The relation between the refractive index and the concentration depends on the. In the immersion method by focal masking, advantage is taken of the fact that the wavelength dispersions of refractive index of the common organic immersion liquids are appreciably greater than those of most inorganic. It is defined as, where c is the speed of light in vacuum and v is the phase velocity of light in the medium.
Different glass types exhibit different dispersion curves. However a professor has asked me how would i determine whether or not an object is transparent or not, simply by being given the refractive index n of. Similarly, measurement of refractive index is widely used in analytical chemistry to determine the concentration of solutions. Students determine the refractive index of a liquid with a simple technique using a semicircular hollow block.
Refractive index definition pdf the refractive index is a unitless parameter, equal to 1 for a vacuum and. A simple method for measuring the refractive index of liquid is presented. Now lock the laser in place and do not move it for the remainder of the experiment. Pdf determination of refractive index of a liquid using. Microscopic theory of the refractive index article pdf available in optik international journal for light and electron optics 140 october 2015 with 1,716 reads how we measure reads. Thus n vac can be obtained by measuring the two angles. The graph, concentration verses refractive index for salt solution is shown above. Drop an object pin into the beaker of water so that it sinks to the bottom. The homemade light intensity detector uses an led and multimeter, which are relatively inexpensive.
Metameterial refraction characteristics within the millimeter. Determining the refractive index of a liquid chm 220 refractive index is a measure of the how much a liquid bends light as it enters and leaves the solution. A simple method to measure the refractive index lee white and. Note that if you see the phrase the refractive index of glass is 1. Theory and experiment an innovative approach is presented to interpret the refractive index of binary liquid. Refractive index of sugar solution and salt solution were calculated with different apparatus setup 1. Absolute refractive index is a measure of optical density n so the smaller the n of a substance, the greater the speed of light in that substance. To determine the refractive index of a prism by using a spectrometer. Physics lab report refractive index jlk95yjg2745 idocpub. Refractiveindexmatched hydrogel materials for measuring. In the experiment the interferometer was used with wave front division by two mirrors, one of. I am doing an investigation into determing the refractive index of perspex for an assignment. In this paper the main properties of a prism of initially unknown refractive index and material will be analysed.
As such, it is an automated system which measures the refractive index of microscopic glass fragments by monitoring the change in refractive index of calibrated oils as they are heated and cooled. Osa measurement of the refractive index of liquid using. Refractive index is a number that indicates how fast light travels in a transparent medium. The refractive index is a unitless number, between 1. I was wondering what will happen if you have two aqueous solutions with the same refractive index and you mix them. To measure the refractive index of a liquid diagram apparatus beaker of water plane mirror two pins retort stand metre stick procedure 1.
The mirror with the longest focal length, 30 cm, gave the refractive index to be 1. It is worth another look at current and emerging technol ogies to satisfy the spirit of riskbased approaches to manufacturing. This is described by snells law of refraction, n 1 sin. Combined theoretical and experimental study of refractive. Different glass types exhibit different dispersion curves, as shown below. Effect of molecular weight on the refractive index. You can calculate the refractive index of the liquid using the equation, you can verify your results by clicking on the show result button.
1566 307 314 634 849 827 930 1245 1581 1383 1143 976 1107 999 501 758 160 935 358 518 692 865 1016 1096 1343 1516 1371 159 1427 600 1209 195 416 1215 823 954 200 533 1389 1050 358 669