Electromagnetic (EM) waves are waves of electric and magnetic fields that travel through space at the speed of light. These waves do not require a medium to propagate, meaning they can travel through a vacuum (such as space).
Key Properties of Electromagnetic Waves:
- Transverse Nature – The electric and magnetic fields oscillate perpendicular to each other and to the direction of wave propagation.
- Speed – In a vacuum, all electromagnetic waves travel at the speed of light (~299,792,458 m/s or ~3.00 × 10⁸ m/s).
- Energy Transfer – They carry energy and momentum, which can interact with matter.
- No Medium Required – Unlike sound or water waves, they do not need air, water, or any material to travel.
Electromagnetic Spectrum:
EM waves exist in different forms, classified by their wavelength and frequency. From longest wavelength (lowest energy) to shortest wavelength (highest energy), they include:
- Radio Waves – Used in communication (radio, TV, WiFi).
- Microwaves – Used in cooking (microwave ovens) and radar.
- Infrared (IR) Rays – Heat radiation, night vision, and remote controls.
- Visible Light – The only EM waves visible to the human eye (ROYGBIV colors).
- Ultraviolet (UV) Rays – Emitted by the Sun, used in sterilization.
- X-rays – Used in medical imaging and security scans.
- Gamma Rays – Produced in nuclear reactions, used in cancer treatment.