The Wave Equation — Waves & The Electromagnetic Spectrum | IGCSE Physics

Exam Frequency Analysis

Past paper frequency (2018 to 2024)

This topic accounts for approximately 14% of your exam marks.

stable

High

Stable14%

Wave equation (v = fλ), transverse vs longitudinal and EM spectrum properties tested consistently.

v = f × λ

where:
- v = wave speed (m/s)
- f = frequency (Hz)
- λ = wavelength (m)
The equation applies to every kind of , including sound, water ripples, and every band of the electromagnetic spectrum
Rearrangements:
- λ = v / f (a higher-frequency wave has a shorter wavelength at fixed speed)
- f = v / λ

f = 1 / T

When a question gives you the period rather than the frequency, find f first, then use the wave equation

Worked example

Calculating frequency using the wave equation

A radio signal travels at 3.0 × 10⁸ m/s and has a wavelength of 1.5 m. Calculate the frequency of the signal.

Solution: