Magnetism Flashcards
(25 cards)
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
