DrG-Physics · Refraction · SQA Higher Physics revision

A focused single-topic revision companion on Refraction for SQA Higher ‘Particles & Waves’ (the wave half — Volume II — Light). Covers refractive index, Snell’s law, the critical angle, total internal reflection, and optical fibres.

The DrG-Physics revision companion is not a worksheet. It is a structured exam-thinking guide — built around the way an SQA marker reads your script. Each worked solution leads with the relationship the examiner is looking for, substitutes cleanly, and evaluates with units. Every question carries a marker-aligned command-word tag (CALCULATE · 2 marks · STATE + JUSTIFY) so students learn what kind of answer earns each mark.

WHAT’S INSIDE
• Theory chapter on refraction, refractive index, and total internal reflection, with two diagrams: refraction at a boundary, and the three TIR cases (below, equal, above critical angle)
• Five SQA-style questions covering Snell’s law (air to glass), critical angle and TIR judgement, wavelength changes on refraction, optical-fibre principle, and the general two-medium Snell’s law
• Special focus on the conceptual point SQA examines every year: speed and wavelength change on refraction; frequency does NOT
• Examiner’s Note after every question naming the typical pitfall (calculator in radians, angles measured from the surface)
• Do/Don’t pair to reinforce SQA marking conventions

TWO EDITIONS · ONE DOWNLOAD
• EXAM Edition — clean, concise solutions for printing and exam-style practice
• STUDY Edition — same content plus ‘Why’ reasoning panels before each part

PART OF THE SERIES
One of four topics in ‘Particles & Waves Vol II — Light’. Try PW01 — Standard Model FREE to experience the approach.

Written and produced by Dr Godoy, GTCS-registered Physics teacher, Edinburgh.