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Homework Help: Anyone know of experiments to calculate the refractive indexes of liquids?

  1. Jan 12, 2010 #1
    For my AH Physics investigation I'm going to research the refractive index of a liquid and need a few different experiment ideas to perform within my pretty basic school lab.

    An example of a feasible experiment would be much appreciated!

    I have thought about changing the density/temperature of the liquid, and possibly use different light sources. But i need more variables please.
    Last edited: Jan 12, 2010
  2. jcsd
  3. Jan 12, 2010 #2


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    Think of measuring it directly vs ways of comparing it with a known material
  4. Jan 12, 2010 #3
    The refractive index is the ratio between the speed of light in vacuum and the speed of light in the refracting material.

    [tex]n=\frac{c}{v}[/tex] where [tex]v[/tex] is the speed of light inside the material.

    The two main consequences of this relationship are the one summarized in Snell's Law, and the fact that the actual velocity of light in the material is slower.

    An interesting phenomenon is that of total internal reflection, an experiment on that subject could be very interesting as well.

    If you've got access to equipment that's accurate enough, you could actually look at the speed of light itself in the material.

    If you're familiar with the concept of polarization and Brewster's Angle and have access to a polarizer, you can design an experiment that would include that concept as well.

    Some other possible experiments could be on dispersion (The dependence of the index of refraction on wavelength) in the material and the formation of rainbows, for instance.

    The possibilities are really endless!

    If you really want a good experiment, I think you should find a concept or phenomenon that has to do with the index of refraction that really interests you (I posted a couple of examples, but really there are many many more), and perhaps even something that's visually stunning to wow the class, and just enjoy the experiment yourself.
  5. Jan 13, 2010 #4
    Thanks for your help, i'll see how things go. its more a project to be handed in with proof of results etc than performed in front of a class however. It requires a theory and hence more than one way of proving it, ergo i need more than on experiment. But thanks for the ideas!
  6. Jan 13, 2010 #5
    Rather than having an air to liquid medium (which I assume is what your going to do) how about a liquid to liquid medium? You can calculate where the light source should come out of medium 1 using snells law etc and then show that if you use a different medium that the light source will refract out at a different place. Just an idea :)
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