Refraction Lab is a free interactive simulation of light refraction for GCSE Physics (Edexcel IGCSE 4PH1, spec point 3.19). Students vary the angle of incidence and measure the angle of refraction to investigate Snell's law and find the refractive index of glass. Includes worksheet and self-marking quiz.
Aim: To investigate the relationship between the angle of incidence and the angle of refraction when light passes from one medium to another.
Results table
i (°)
r (°)
sin i
sin r
Action
Set the top medium to Air (n₁ = 1.00) and the bottom medium to Glass.
Set the angle of incidence to 10°. Record the angle of incidence i and the angle of refraction r shown in the readout in your results table.
Increase the angle of incidence in 10° steps up to 80°, recording i and r at each step.
For each row, calculate sin i and sin r.
Plot a graph of sin i (x-axis) against sin r (y-axis).
Measure the gradient of the graph. What do you notice about its value, and what does it represent?
Repeat with the bottom medium set to Diamond. How does the gradient change, and what does this tell you about the refractive index of diamond compared with glass?