A mobile phone sends signals using microwaves.
The frequency of the microwaves is 1.8 GHz1.8\ \text{GHz}1.8 GHz.
The speed of microwaves is 3.0 × 108 m/s.
Calculate the wavelength of the microwaves.
A radio station broadcasts using radio waves with a frequency of 100 MHz.
State whether the wavelength of these radio waves is longer or shorter than the wavelength of the microwaves in (a).
Give a reason for your answer.
Microwaves are also used to cook food in a microwave oven.
Explain how the microwaves heat the food.
48 exam-style questions on OCR GCSE Physics 5.2 The electromagnetic spectrum, covering 5.2.1 Electromagnetic waves in space, 5.2.2 Energy transfer by electromagnetic waves, 5.2.3 Frequency and wavelength across the spectrum, 5.2.4 Groups of the electromagnetic spectrum, 5.2.5 Visible light and the limits of human sight, 5.2.6 Light as an electromagnetic wave, 5.2.7 Uses of electromagnetic waves, 5.2.8 Hazards of ultraviolet, X-rays and gamma rays, 5.2.9 Ultrasound and imaging inside the body, and 5.2.10 Radio waves and oscillating circuits. Each one has a worked solution and a mark scheme showing where the marks go.