ELECTROMAGNETISM

Shweta G Menon

Roll No: 209

Physical Science

KUCTE, Aryad, Alappuzha

Electromagnetism ?

Originally electricity and magnetism were thought of as two separate

forces.

James Clerk Maxwell's 1873 Treatise on Electricity and Magnetism.

A magnetic field that is produced by a current of electricity.

Electromagnetism, or the electromagnetic force is one of the

four fundamental interactions in nature.

James Clerk Maxwell

Hans Christian Ørsted’s observation (21 April 1820)

The magnetic needle deflected from magnetic north when the

electric current from the battery switched on & off.

Magnetic fields radiate from all sides of a wire carrying an electric

current.

Confirmed a direct relationship between electricity and magnetism.

Magnetic field around a straight conductor carrying current

Hans Christian Oersted

This findings resulted in intensive research throughout the scientific

community in electrodynamics.

French physicist André-Marie Ampère's developments of a single

mathematical form for electromagnetism.

Ørsted's discovery also represented a major step toward a unified

concept of energy.

Unsung Hero

• In 1802 Gian Domenico Romagnosi, an Italian legal scholar, deflected

a magnetic needle by electrostatic charges.

• Actually, no galvanic current existed in the setup and hence no

electromagnetism was present.

• An account of the discovery was published in 1802 in an Italian

newspaper.

Electromagnetism in Daily Life

Electric motor

Electric Fan

Motor Car

Washing Machine

Circuit Breaker

Mixer Grinder

Computer Hardwares

Mobiles

MRI Scan

The list is everending.............

Some Interesting Uses of Electromagnets

Magnetic Resonance Imaging (MRI)

A popular method of medical imaging that provides views of tissues in

the body.

It is a huge scanner containing a solenoid made of superconductors.

Trains that Float by Magnetic Levitation

Generators

A generator is a device that uses induction to convert mechanicalenergy into electrical energy.

The magnet near the coil alternates from north to south as the diskspins.

The direction of the current reverses every time a magnet passes thecoil.

Transformers

Transformers are extremely useful because they efficiently change

voltage and current, while providing the same total power.

The transformer uses electromagnetic induction, similar to a generator.