PHYSICS CONNECTION
Path difference becomes phase difference
Two coherent waves can reinforce or cancel because their displacements add. Path difference determines their phase relationship at the observation point.
One wavelength of path difference = 2π phase difference
Follow the reasoning
- Check that the sources have a stable phase relationship.
- Express the path difference as a fraction of wavelength.
- Add the displacements with their phases.
OFFICIAL OCR QUESTIONS
Try it in a past paper 2
Open the question, then use its mark scheme to check your work.
Question 7(b)
Use a double-slit fringe pattern to determine slit separation.
Question 5
Use ripple-tank wave speed, path difference and phase to explain interference.
A curated collection checked against the question papers and mark schemes; not a complete past-paper catalogue. Links open official OCR PDFs in a new tab.
ORIGINAL PHYSICSUK QUESTIONS
Put the ideas to work
More practice is on its way
No PhysicsUK question linked yet. New eligible questions appear here as the bank grows.
Specification outcomes (4)
- 4.4.1(b)(i) Define displacement, amplitude, wavelength, period, phase difference, frequency and speed of a wave.
- 4.4.1(e) Interpret graphs of transverse and longitudinal waves.
- 4.4.3(c) Define and describe interference, coherence, path difference and phase difference.
- 4.4.3(d) Explain constructive and destructive interference in terms of path and phase difference.