revision 2 year 8

The closer to the wire coils the _____ the magnetic field.

• What's a magnetic field?

• Stronger

• Weaker

• Same

a device that uses an electric current to produce motion

• electromagnet

• electric motor

• electric generator

• electromagnetism

a magnet created by wrapping a current-carrying wire around a ferromagnetic core

• electromagnet

• electric motor

• electric generator

• electromagnetism

The strength of an electromagnet can be increased by reducing the number of turns on the wire coil so that more current can flow.

• True

• False

The more loops in a coil of wire around the core of an electromagnet, the stronger the magnetic force.

• True

• False

As a nail approaches the south pole of a magnet, what happens to its magnetic domains?

• The north poles of the domains point toward the magnet.

• The south poles of the domains point toward the magnet.

• The domains spin, but end up in no particular pattern.

• The domains remain unaffected by the magnet.

The picture is an example of an:

• Electric circuit
• Electromagnet
• Electric nail
• Electric power cell

Probably the most useful thing about electromagnets is that they can be turned ________ and ________.

• on, off

• positive, negative

• north, south

• on, negative

A current flowing through a wire is surrounded by a ____ field.

• positive

• magnetic

• negative

• electron

Which of these is the best definition of electromagnetism?

• the use of electrical energy to produce magnets

• the use of magnets to generate electric current

• the interaction of electricity and magnetism

• the appearance in nature of objects that have both electric and magnetic fields