WAEC Physics 2021 Paper

Concept:In the electromagnetic spectrum, wavelength decreases as frequency increases.Explanation:Arrange radiations from longest wavelength to shortest wavelength. Radio waves have the longest wavelength among the given options. Infrared radiations have shorter wavelengths than radio waves. X-rays have the shortest wavelength among the given options. Therefore, the decreasing order of wavelength is: $$\text{Radio waves} > \text{Infrared radiations} > \text{X-rays}$$Answer:B. Radio waves > infrared radiations > X-rays