A student measures refraction for incident angles of 20∘20^\circ20∘, 40∘ 40^\circ\,40∘ and 60∘60^\circ60∘. For each measurement, the student uses a different glass block.
Which change is needed to investigate the effect of angle of incidence alone?
Keep the angle of refraction fixed and use the different blocks.
Keep changing the blocks and repeat each reading three times.
Use the same block and vary only the angle of incidence.
Use the same angle of incidence and vary only the block.
84 exam-style questions on Edexcel GCSE Physics 5.2 The electromagnetic spectrum, covering 5.2.1 Electromagnetic waves and refraction in glass (core practical), 5.2.2 Groups of the electromagnetic spectrum, 5.2.3 Wavelength-dependent behaviour of EM waves, and 5.2.4 Velocities of EM waves in different substances. Each one has a worked solution and a mark scheme showing where the marks go.