Integrated Science
Refraction of Light and Snell’s Law
(for Integrated Science)
Aim:
 To investigate the relationship between the angle of incidence and
the angle of refraction.
 To investigate the validity of Snell’s law.
 To determine the index of refraction for a glass block.
Criteria
assessed
Aspect
1
2
3
D
DCP/12
Semi-Circular Block
 Place the block on top of paper and trace around it.
 Shine a laser or beam from a laser onto it and through it.
 Trace the incoming ray and the exiting ray. Label each ray as so
you know that they are part of the same data point.
 Change the angle of your incoming beam several times to collect a
sufficient amount of data.
 Measure the incident and refracted angles.
CE /12
i
Diagram:
Apparatus:
Transparent block
(rectangular or semicircular),
light source (laser or narrow
beam), protractor, straight
edge
r
Theory:
Snell’s Law
n=
𝒔𝒊𝒏 𝒊
𝒔𝒊𝒏 𝒓
Data Collection:
 Complete three trials and take average
 Record all values for your refracted and incident angles in a suitable table.
 Your results table and the presentation of data should include any uncertainties associated with the
apparatus that you have used.
Data Processing and Presentation:
 Draw a suitable graph that will allow you to find the refractive index of your chosen block.
angles. (sin i vs sin r )
 For each data point, find the index of refraction of light. You can do this with a calculator, or have
excel do this if you are especially clever. Find the average of all these values. Compare with the
relationship your
Conclusion and Evaluation:
 What is your value (from graph) for the index of refraction of your block?
 How does this compare to the known value?
 Cite where you find this known value!
 How could you improve this experiment?
© 2012 Richard Reilly
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