A wave travels from transparent substance P into transparent substance Q.
Its speed increases by 25%. Its wavelength in P is 480 nm480\ \mathrm{nm}480 nm.
Which pair gives its wavelength in Q and its frequency in Q compared with P?
Wavelength 384 nm384\ \mathrm{nm}384 nm; frequency unchanged.
Wavelength 600 nm600\ \mathrm{nm}600 nm; frequency increased by 25%25\%25%.
Wavelength 600 nm600\ \mathrm{nm}600 nm; frequency unchanged.
Wavelength 384 nm384\ \mathrm{nm}384 nm; frequency increased by 25%25\%25%.
84 exam-style questions on Edexcel GCSE Physics 5.2 The electromagnetic spectrum, covering 5.2.1 Electromagnetic waves and refraction in glass (core practical), 5.2.2 Groups of the electromagnetic spectrum, 5.2.3 Wavelength-dependent behaviour of EM waves, and 5.2.4 Velocities of EM waves in different substances. Each one has a worked solution and a mark scheme showing where the marks go.