Which electromagnetic wave is primarily used for communication?

Radio waves are primarily used for communication due to their ability to travel long distances and penetrate through various materials, which makes them ideal for transmitting information without significant loss. They operate at lower frequencies compared to other electromagnetic waves, which allows them to carry signals over vast areas, making them suitable for applications such as radio broadcasting, television, and mobile phone communications.

The properties of radio waves, including their long wavelength and low energy, allow them to be easily generated and manipulated by antennas, facilitating effective communication systems. Additionally, radio waves can reflect off the ionosphere, extending their range even further.

In contrast, the other types of electromagnetic waves mentioned have different applications. Gamma rays and X-rays, for example, have much higher frequencies and energy, making them suitable primarily for medical imaging and treatments, as well as some industrial applications. Ultraviolet rays are also not used for communication; instead, they have applications in sterilization and fluorescent lighting.