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Overview
Electromagnetism connects electric charge, electric fields, magnetic fields, currents, forces, induction, light, and electromagnetic waves. Electric and magnetic effects are not separate topics in the deeper theory. They are related aspects of one electromagnetic interaction.
Electric and Magnetic Connection
Electric charges create electric fields. Moving charges and currents create magnetic fields. Changing magnetic fields can create electric fields, and changing electric fields are connected to magnetic fields.
Currents and Magnetism
An electric current produces a magnetic field around the conductor. Coils of wire can strengthen and shape this magnetic field.
Electromagnets
An electromagnet uses electric current to produce magnetism. Turning the current on or off controls the magnetic field.
Maxwell's Unification
Maxwell's equations unified electricity, magnetism, and light by showing that changing electric and magnetic fields can sustain electromagnetic waves.
Electromagnetic Waves
Electromagnetic waves include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Technology
Electromagnetism underlies motors, generators, transformers, radio, antennas, power grids, electronics, MRI, speakers, sensors, and communication systems.
Force and Energy
Electromagnetic systems transfer energy and exert forces through fields. These effects power machines, transmit signals, and structure matter.
Common Mistakes
A common mistake is treating electricity and magnetism as unrelated. Moving charges and changing fields connect the two.
Why This Matters in Physics
Electromagnetism is one of the major pillars of physics and one of the foundations of modern technology.