Which statement correctly describes two coherent light sources?
They have different frequencies and a constant phase difference.
They have the same frequency and a constant phase difference.
They have the same amplitude and a continuously changing phase difference.
They have different wavelengths and a constant phase difference.
237 exam-style questions on CIE IGCSE Physics General properties of waves, covering General properties of waves. Each one has a worked solution and a mark scheme showing where the marks go.