Physics Final Test - Part 4

magnetic force

attractive or repulsive, field force (no contact needed)

magnetic poles

two poles: one north, one south

opposite poles attract, like poles repel

there is no such thing as a monopole (one sided magnet) or a magnetic charge

magnet

produce and are affected by a magnetic field

magnetic fields

the area around a magnet where it can exert a force other magnets

symbol for magnetic field

symbol for magneitc field is B

unit for magnetic field

unit for magnetic field is Tesla (T)

direction of the magnetic field is the direction…

direction of the magnetic field is the direction the north needle of a compass would point if placed in that field

magnetic field lines

• magnitude (strength) = closeness of the lines

• directions=arrows

• they always run from north pole to sourth pole

• they never cross

moving electric charges create…

moving electric charges create magnetic fields

domains are …

domains are ferromagnetic atoms group and facing one way (lined up in the same direction).

magnet stronger when domians are strongly in alignment.

temporary magnet

the domains are only aligned when it is in a strong mag. field

ex: paperclip

permanent magnet

the domains stay aligned unless forced out of alignment

ex: bar magnet

magnets create…

magnets create magnetic fields, which exert forces other magnets

motor →

moving charges (electric energy) + magnetic field (magnetic force) = KE

moving charges: power source sends current through the coil

magnetic field: there is a permanent magnet in the motor

KE: the coil is pushed in a circle spinning the axle

← Generator

moving charges (electric energy) = magnetic field (magnetic force) + KE

moving charges: this causes electrons to move through the wire (current)

magnetic field: there is a permanent magnet in th generator

KE: external KE pushes the coils in a circle