Chapter 8: Magnetism and Its Uses

Turbine

________: a large wheel that rotates when pushed by water, wind, or steam.

Hans Christian Oersted

In 1820, ________, a Danish physics teacher, found that electricity and magnetism are related.

Power plants

________ commonly produce alternating current because the voltage can be increased or decreased with transformers.

Transformer

________: a device that increases or decreases the voltage of an alternating current.

solenoid

If the ________ is wrapped around an iron core, an electro- magnet is formed.

Electromagnet

________: a temporary magnet made by wrapping a wire coil carrying a current around an iron core.

electrical energy

The alternator provides ________ to operate lights and other accessories.

Electromagnetic Induction

________: The generation of a current by a changing magnetic field.

Galvanometers

________: devices that use an electromagnet to measure electric current.

Generator

________: uses electromagnetic induction to transform mechanical energy into electrical energy.

electric motors

Both generators and ________ use magnets to produce energy conversions between electrical and mechanical energy.

Solenoid

________: A single wire wrapped into a cylindrical wire coil.

galvanometer

In a(n) ________, the electromagnet is connected to a small spring.

Electromagnets

________ are temporary magnets because the magnetic field is present only when current is flowing in the solenoid.

secondary coil

In a step- up transformer the number of wire turns on the ________ is greater than the number of turns on the primary coil.

Electric Motor

________: a device that changes electrical energy into mechanical energy.

transformer

A(n) ________ is made of a primary coil and a secondary coil.

transformer

A(n) ________ that decreases the voltage so that the output voltage is less than the input voltage is a step- down ________.

Magnetism

refers to the properties and interactions of magnets

Magnetic Field

exerts a force on other magnets and objects made of magnetic materials

Magnetic Poles

where the magnetic force exerted by the magnet is strongest

Magnetic Domains

The groups of atoms with aligned magnetic poles

Electromagnet

a temporary magnet made by wrapping a wire coil carrying a current around an iron core

Solenoid

A single wire wrapped into a cylindrical wire coil

Galvanometers

devices that use an electromagnet to measure electric current

Electric Motor

a device that changes electrical energy into mechanical energy

Direct current

flows only in one direction through a wire

Alternating Current

reverses the direction of the current in a regular pattern

Transformer

a device that increases or decreases the voltage of an alternating current