Magnetism Flashcards
Magnetism refers to…
the properties and interactions of magnets
Magnetic fields are strongest where?
closer to the magnet
what surrounds a magnet?
a magnetic field
magnetic poles are…
areas where the magnetic force exerted is the strongest
true or false: all magnets have a north and south pole
true
magnetic field lines always go…
north to south
why does the north part of a compass point north if like poles repel?
the north pole of earth is actually the south part of the magnetic core of earth. (pg. 427 in book)
what is a compass?
a small bar magnet free to rotate and align with earth’s poles
what are the 3 metals that can become permanent magnets?
Cobalt, Iron, Nickel (CIN)
groups of atoms with aligned magnetic fields are called
magnetic domains
in a magnetic domain, like poles point in…
the same direction
magnets become weaker when…
heated up or dropped a lot
both cause the atoms in the domains to slip out of alignment
you can make a magnet strong again by…
bringing it close to or in contact with a stronger magnetic field
(the stronger magnet re-aligns the domains in the weak magnet)
even permanent magnets can lose their magnetic properties if they are…
heated up
generators turn _______ energy into ________ energy
mechanical, electrical
an electric motor turns ________ energy into _______ energy
electrical, mechanical
three examples of generators
wind turbine, water turbine/dam, steam turbine
an alternating current goes in which direction?
two different directions
a direct current goes in what direction?
only one direction
what do transformers do?
they either increase or decrease the voltage of an alternating current
what does a step-up transformer do?
increases voltage
what does a step-down transformer do?
decreases voltage
how does a magnet exert force?
they attract or repel
what flips the current and keeps the electromagnets (solenoids) spinning?
commutator
when the brushes hit the gaps on the commutator, what happens to the current?
the current stops and the solenoids keep spinning due to inertia
