Electromagnetic
The term Electromagnetic pertains to the interaction of electric and magnetic fields, often described within the framework of Electromagnetism, which is one of the four fundamental forces of nature. This force is responsible for the behavior of Electric charge and Magnetic field, and their interactions lead to the creation of Electromagnetic radiation, such as light, radio waves, and X-rays.
Historical Context
- 1820: Hans Christian Ørsted discovered that a magnetic field is generated around a wire through which an electric current flows. This was a pivotal moment linking electricity and magnetism.
- 1831: Michael Faraday and Joseph Henry independently discovered electromagnetic induction, which states that an electric current can be induced in a conductor by changing the magnetic field around it.
- 1864: James Clerk Maxwell formulated the Maxwell's equations, a set of four mathematical equations that describe how electric and magnetic fields interact.
Fundamental Principles
Electromagnetism is governed by several key principles:
- Coulomb's Law: Describes the electric force between two charges.
- Ampere's Law: Relates magnetic fields to electric currents.
- Faraday's Law of Induction: Explains how a change in magnetic field induces an electromotive force.
- Maxwell's Equations: Provide a complete description of electromagnetic phenomena, including the prediction of electromagnetic waves.
Electromagnetic Waves
Electromagnetic waves are created when an electric charge accelerates, producing synchronized oscillations in electric and magnetic fields. These waves travel at the speed of light in a vacuum, which is approximately 299,792 kilometers per second (about 186,282 miles per second). The spectrum of electromagnetic waves includes:
- Radio waves
- Microwaves
- Infrared radiation
- Visible light
- Ultraviolet light
- X-rays
- Gamma rays
Applications
The understanding and application of electromagnetic principles have led to numerous technological advancements:
References
See Also