Identify two of the following options that apply to an infrasound wave travelling in air:
Calculate the wavelength in a vacuum of gamma rays of frequency 2.5×1020 Hz2.5 \times 10^{20}\text{ Hz}2.5×1020 Hz.
A radiologist performs a chest X-ray on a patient. Explain why it is safe for the patient to undergo this brief procedure, but the radiologist must stand behind a protective lead screen or in another room during the exposure.
State, with a reason, why ultraviolet (UV) sterilising chambers are designed with a safety mechanism that automatically turns off the UV light when the door is opened.
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.