RAD Physics - Chapter 7: Magnetism

Magnetism

Ability to attract iron, cobalt, or nickel

A Magnet

Anything that attracts iron, cobalt, or nickel is called?

Earth & loadstone

___ & ___ are natural magnets

Artificial permanent magnet

piece of hard steel in the shape of a bar shape or horseshoe that has been artificially magnetized so that it is capable attracting iron

Electromagnet

temporary magnets that are produced by electric currents

2 (north and south)

how many poles does a magnet have?

repel, attract

Like magnetic poles ___, unlike poles ___

its own magnet

When breaking a magnet, each piece becomes ___

magnetized

Heating or hammering steel while it lies near a magnet causes the steel to become ___

magnetized

Stroking an iron bar with a magnet causes the iron bar to become ___

magnetized

Jarring test tube of iron filings near a magnet causes the iron filings to become ___

electron spin

Magnetism is attributed to the property of ___

1) Natural magnet

2) Artificial permanent magnet

3) Electromagnet

3 classification of magnets?

magnet

Every electron is considered a tiny little ___

cancel out

If the electron spins of an atom's electrons are aligned oppositely, their magnetic fields ___

magnetic dipole or magnetic moment

Atoms of magnetic materials have 2 more electrons spinning in one direction than in the opposite direction, creating a ___ or ___

domains

Billions of these dipoles occur in ___, all dipoles are aligned in the same direction (north poles face in one directions + all south poles face opposite direction)

Magnetic Element

more electrons spinning in one direction than the other (potential to become magnetized)

non-magnetized

In the ___ state of iron, the domains are in a random state if disorder

magnetized

In the ___ state of iron, the domains are aligned with all north poles pointing in one direction and south poles pointing in the opposite direction

Nonmagnetic Element

this material cannot become magnetized?

nonmagnetic

In ___ elements, just as many electrons spin in one direction as the other

magnetic field

Surrounding a magnet there is a zone of influence called a ___

stronger

Closer the lines of force are = ___ magnetic field

proportional

The strength of the magnetic field is ___ to the # of lines per square centimeter

magnetic field lines

Lines of force mean the same thing as ___?

north to south, south to north

Lines of force are directed outside of the magnet from the ___ pole to the ___ pole, and within the magnet from the ___ pole to ___ pole

repel, attract

lines of force in the same direction will ___, opposite direction will ___

magnetic, nonmagnetic

Lines of force are affected by ___ materials and not affected by ___ materials

Magnetic Induction

how change a magnetic element from a nonmagnetized state to the magnetized state

opposite

When a piece of nonmagnetized iron is brought near one pole of a magnet, the end of the iron nearest to the pole assumes the ___ polarity resulting in a force of attraction between the 2

randomize

When iron is removed from the magnetic field, the magnetic domains ___, resulting in the iron no longer being magnetized

Permeability

the ease with which a material can be magnetized

High permeability

easy to magnetize

low permeability

difficult to magnetize

Retentivity

the ability of a magnet to resist demagnetization

High retentivity

hard to demagnetize

low retentivity

easy to demagnetize

low

High Permeability = ___ retentivity

high

Low Permeability = ___ retentivity

Ferromagnetic

strongly attracted by a magnet

Ferromagnetic examples

examples are Iron, cobalt, nickel

Paramagnetic

weakly attracted by a magnet

Paramagnetic examples

example is Platinum

Nonmagnetic

not attracted by a magnet

Nonmagnetic examples

examples are Wood, glass, plastic

Diamagnetic

repelled by a magnet

Diamagnetic examples

examples are Beryllium and bismuth