IGCSE Physics Practice Exam 2025 - Free International General Certificate of Secondary Education Practice Questions and Study Guide

Radio waves are a type of electromagnetic radiation and they possess the longest wavelengths within the electromagnetic spectrum. Wavelength is a critical factor that determines the characteristics and behavior of different waves. Radio waves can range from about one millimeter to several kilometers in length, which is much longer than the wavelengths of X-rays, visible light, and ultraviolet rays.

X-rays have significantly shorter wavelengths, typically in the range of 0.01 to 10 nanometers. Visible light, which is the portion of the electromagnetic spectrum detectable by the human eye, has wavelengths ranging from approximately 400 nanometers (violet) to 700 nanometers (red). Ultraviolet rays also fall within a shorter wavelength range, typically from about 10 nanometers to 400 nanometers.

The longer wavelengths of radio waves allow them to be used effectively in communication technologies like radio and television broadcasting, where their ability to propagate over long distances is advantageous.