Which statement correctly describes all electromagnetic waves travelling in a vacuum?
They have the same wavelength.
They have the same frequency.
They travel at the same speed of 3.0×108 m/s3.0 \times 10^8 \text{ m/s}3.0×108 m/s.
They are longitudinal waves.
198 exam-style questions on CIE IGCSE Physics Electromagnetic spectrum, covering Electromagnetic spectrum. Each one has a worked solution and a mark scheme showing where the marks go.