A student investigates the refraction of a monochromatic ray of light as it passes from air into a semi-circular crown glass block. They measure the angle of incidence, θ1\theta_1θ1, and the angle of refraction, θ2\theta_2θ2, at the boundary.
Their plotted experimental results and curve of best fit are shown on the graph below:

Explain how the graph demonstrates that the angle of refraction is not directly proportional to the angle of incidence.
Practise AQA GCSE Physics Electromagnetic waves with exam-style questions for Foundation and Higher tier. 52 questions covering Types of electromagnetic waves, Properties of electromagnetic waves 1, Properties of electromagnetic waves 2, Uses and applications of electromagnetic waves, Lenses (physics only), and Visible light (physics only), matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.