Electromagnetism Flashcards
Science Test
Electromagnet
a magnet created by wrapping a current-carrying wire around a ferromagnetic core.
Electric Motor
a device that uses an electric current to produce motion.
Electric Generator
a device that uses a magnetic field to transform mechanical energy to electrical energy
Direct Current
an electric current that continually flows.
Alternating Current
an electric current that changes direction in a regular pattern.
Electromagnetism
the interactions between electric charges and magnets
How are moving electric charges and magnetic fields related?
all electric charges have magnetic fields surrounding the charges.
What happens to the magnetic field of a current carrying wire when the current is turned off?
the charged particles stop moving.
The magnetic field around a current carrying wire is ______________ to the wire.
perpendicular
What affects the strength of a magnetic field around a current? (3)
distance, voltage, number of coils
By changing the current in the wire, you can change the__________ and __________ poles of an electromagnet.
north south
What happens if you put a magnetic material inside of a current-carrying coil of wire?
the magnetic material moves because the magnetic field around the wire applies a force.
Why are electromagnets more useful than permanent magnets?
because you can turn off a electromagnet but you can not do that to a permanent magnet.
What happens to the north and south poles of an electromagnet if the current reverses?
the poles are reversed
In the example of a simple electric motor, electric energy is transferred into____________ energy.
Mechanical
Electric motors produce_______.
motion
List the three main parts of an electric motor:
coil of wire connected to a rotating shaft, permeant magnet, source of electric energy
What happens when a magnet is moved through a wire coil that is part of a closed electric circuit?
An electric current is produced
What happens to the current when you move a magnet into a coil, stop, then pull the magnet out?
A current in the opposite direction is created as the magnet is pulled out, the current stops when the magnet stops, while the magnet moves into the coil, a current is created.
List the ways you could modify an electric generator to increase the strength of the current.
stronger magnet, number of coils, faster motion, less perpendicular
