Electromagnetic induction

Science

Definition

Electromagnetic induction is the production of an electromotive force (voltage) across a conductor when it is exposed to a changing magnetic field. Discovered by Michael Faraday, this principle is the basis for electric generators and transformers.

Examples

  • Electric generators at power plants use spinning turbines in magnetic fields to induce current
  • Transformers use electromagnetic induction to step voltage up or down for power transmission
  • Wireless phone chargers use induction to transfer energy through changing magnetic fields
Key Fact

Faraday's Law: EMF = -NΔΦ/Δt, where N is the number of coil turns and ΔΦ/Δt is the rate of change of magnetic flux.

Related Terms

Electromagnets Magnetic fields Circuits Electric charge

Study This Concept

Practice electromagnetic induction with free review games in these units:

Physics Unit 9: Magnetism