Chapter 7: Magnetism and Its Uses Flashcards
refers to the properties and interactions of magnets
magnetism
a region of space that surrounds a magnet and exerts a force on other magnets and objects made of magnetic materials
magnetic field
the regions of a magnet that exert the strongest force
magnetic poles
groups of atoms with aligned magnetic poles
magnetic domains
attractive or repulsive force between electric charges and magnets
electromagnetic force
interaction between electric charges and magnets
electromagnetism
a single wire wrapped into a cylindrical wire coil
solenoid
a temporary magnet created when there is a current in a wire coil
electromagnet
a device that uses an electromagnet to measure electric current
galvanometer
a device that changes electrical energy into mechanical energy
electric motor
the generation of an electric current by a changing magnetic field
electromagnetic induction
uses electromagnetic induction to transform mechanical energy into electrical energy
generator
a large wheel that rotates when pushed by water, wind, or steam
turbine
electric current that is always in one direction through a wire
direct current
electric current that reverses the direction in a regular pattern
alternating current
a device that increases or decreases the voltage of an alternating current
transformer
transformer voltage equation
output voltage (volts) / input voltage (volts) = turns in secondary coil / turns in primary coil
Vout/Vin = N2/N1
magnets are surrounded by a ________ that exerts a ______ on all __________ __________.
magnetic field; force; magnetic materials
magnet exerts force on…
other magnets
atoms in magnetic materials behave like…
magnets
in a permanent magnet, the magnetic domains remain aligned without…
an external magnetic field
an electric current in a wire is surrounded by…
a magnetic field
the electromagnet force is one of the…
fundamental forces
magnetic field strength of an electromagnet can be controlled by:
changing the number of wire loops and by changing the current in the wire
in a simple electric motor, an electromagnet rotates between the poles of a…
permanent magnet
a changing magnetic field produces…
an electric current in a wire loop
a generator transforms mechanical energy into…
electrical energy
direct current is…
current in one direction
alternating current changes direction in…
a regular pattern
a transformer __________ or ___________ the voltage of an alternating current
increases; decreases
