A student performs a refraction experiment with a semicircular transparent block. In the first part of the experiment, they measure the angle α\alphaα between the normal to the flat surface ABABAB of the block and the refracted ray. They record:
α=36∘ \alpha = 36^\circ α=36∘In the second part of the experiment, they position the block and trace a line CFCFCF representing the emergent ray from the flat surface ABABAB. They measure the acute angle β\betaβ between the flat edge ABABAB and the line CFCFCF as:
β=53∘ \beta = 53^\circ β=53∘Calculate the angle θ\thetaθ between the line CFCFCF and the normal to the flat edge ABABAB.
The student suggests that angle α\alphaα should be equal to angle θ\thetaθ. State whether these experimental results support this suggestion and justify your answer.
State two practical precautions that the student should take when placing and viewing pins in this ray-trace experiment to ensure accurate results.
216 exam-style questions on CIE IGCSE Physics 3.2 Light, covering 3.2.1a Reflection of light, 3.2.1b Images in a plane mirror, 3.2.2 Refraction of light, 3.2.2a Refraction of light, 3.2.2b Total internal reflection, 3.2.2c Refractive index and critical angle, 3.2.2d Optical fibres, 3.2.3a Converging and diverging lenses, 3.2.3b Ray diagrams and the nature of images, 3.2.3c Virtual images and the magnifying glass, 3.2.3d Correcting long-sightedness and short-sightedness, and 3.2.4 Dispersion of light. Each one has a worked solution and a mark scheme showing where the marks go.