Eddy current

Definition

Eddy currents are loops of electric current induced within conductors by a changing magnetic field in the conductor. These currents create their own magnetic fields that oppose the original change, leading to energy loss in the form of heat.

5 Must Know Facts For Your Next Test

1. Eddy currents are generated when a conductor experiences a changing magnetic field due to Faraday's Law of Induction.
2. The magnitude of eddy currents is proportional to the rate of change of the magnetic flux and the electrical conductivity of the material.
3. Eddy currents can cause significant energy losses in transformers and other AC machinery, often manifesting as heat.
4. Magnetic damping, utilized in devices like electromagnetic brakes, leverages eddy currents to provide resistance against motion.
5. Techniques such as laminating core materials or using ferrite cores are employed to minimize eddy current losses in electrical devices.

Review Questions

• What is the primary cause of eddy currents in a conductor?
• How do eddy currents affect energy efficiency in electrical devices?
• What methods can be used to reduce eddy current losses?

Related terms

Faraday's Law of Induction:

A fundamental law stating that a change in magnetic flux through a coil induces an electromotive force (EMF) in the coil.

Magnetic Damping:

A phenomenon where moving conductive objects experience resistance due to induced eddy currents opposing their motion.

Electromagnetic Brakes: Braking systems that use magnetic fields to induce eddy currents within conductive materials, generating resistive forces that slow down motion.