A student draws a ray diagram for a convex lens.
Which ray passes through the lens without changing direction?
A ray travelling parallel to the principal axis
A ray passing through the principal focus
A ray passing through the centre of the lens
A ray hitting the lens close to its edge
51 exam-style questions on OCR GCSE Physics 5.3 Wave interactions, covering 5.3.1 Wavelength and how substances affect waves, 5.3.2 Wave velocity in different substances, 5.3.3 Convex and concave lenses, 5.3.4 Ray diagrams for reflection and refraction, and 5.3.5 Colour, absorption and reflection. Each one has a worked solution and a mark scheme showing where the marks go.