Magnetism/Electromagnetism

Magnetism

May be defined as the ability of certain materials to attract iron, cobalt, or nickel

Any materials that attract these materials is called a magnetic

Classifications of magnet

Natural

Artificial  

Electromagnet

What does every magnet have 

Two poles

Laws of magnetism

Every magnet has two poles

Likes poles repel; unlike poles attract

the force between them

Magnetic field

Surrounding every magnet there is a zone of influence 

Magnetic materials

Iron

Nickel 

Cobalt

Magnetic permeability 

Ease with which a given material can be magnetized

Magnetic Retentivity

Ability of magnet to resist demagnetization

Ferromagnetic materials

Strongly attracted by a magnet due to their high permeability 

Paramagnetic materials

Feebly/weakly attracted by a magnet

Nonmagnetic

Not attracted by material; not susceptible to magnetic induction 

Diamagnetic

Usually repelled by a magnet

Every magnet has two poles. What are they called?

North and south 

Which of the following determines the strength of a magnetic field?

The number of flux lines

How are the north poles of two magnets going to affect each other?

Repel

What are the materials called that are slightly repelled by a magnet?

Diamagnetic Materials

What are the magnetic lines called that surround a magnet?

Flux

Which circuit is a battery

DC circuit 

Electromagnetism

branch of physics that deal wit the relationship between electricity and magnetism

What happens when a current flows in a wire helix

one end behaves as though it were the north pole and the opposite end the south pole of a magnet

Solenoid

Helix carry an electric current

Electromagnet

Solenoid with an iron core

What is a helix

coil of wire

Angle that is most optimal between conductor and direction of magnetic field

90 degrees

Electromagnetic induction determined by what four factors 

Self induction

induction of an opposing emf in single cell by its own changing magnetic field

not good

Mutual Induction

Process of inducing a current flow through a secondary coil by posing a varying current through primary cell

Electrical Generator

Converts mechanical energy to electrical energy

What do AC use to generate current

Slip ring

What does DC use to generate current

Commutator Ring

Electrical motor

Converts electrical energy to mechanical energy

What device is used to convert AC to DC as it is transmitted from a generator?

Commutator

An electric current that continually changes direction is known as what type of current?

Alternating