O-Level Physics Optics Practical Handbook (Paper 3)

TL;DR
SEAB’s 2026 O-Level Physics syllabus (6091) lists optics and wave investigations-lenses, mirrors, refraction, wave speed-as staple Paper 3 tasks.
Earn MMO marks by rehearsing precise alignment, consistent ray tracing, and clean oscilloscope or timer readings within the shared apparatus slot.
ACE marks hinge on linking experimental gradients to lens/mirror equations, propagating measurement uncertainty, and proposing refinements grounded in the syllabus skill strands.

1 | What the syllabus expects for optics and waves

• The 2026 O-Level Physics syllabus highlights ray diagrams, refraction (Snell’s law), lens formulae, and wave measurements as core practical experiences. Section 4 (Practical Assessment) explicitly states that Paper 3 tasks sample the four skill strands-Planning (15 %), MMO, PDO, ACE-across these experiments.
• Candidates may be asked to determine focal length, verify $n = \sin i / \sin r$, measure wave speed in a ripple tank, or time a pendulum/elastic-string oscillation (Section 4.3, SEAB 2026 syllabus).
• Apparatus is shared across 55 min rotations, so the syllabus advises efficient setup, neat data tables, and uncertainty awareness. Practical questions can incorporate data-analysis prompts without live apparatus (SEAB 2026 syllabus).

2 | Planning framework before you touch the kit

1. Aim: State the physical relationship you will verify (e.g.