DEL Unit 04: Magnetism

Earth contains magnetic poles.

True

A basic law of magnetism states that unlike poles _____ and like poles _____.

attract; repel

The angular difference between true north and magnetic north is known as the angle of _____.

declination

Magnetic lines of force are referred to as _____.

flux

The three substances that form natural magnets are _____.

iron, nickel, and cobalt

What type of magnets do not require any power or force to maintain their field?

permanent magnets

The north pole of a compass needle points in the direction of the south geographic pole.

False

Man-made permanent magnets retain their magnetism _____ than natural magnets.

longer

What type of magnet depends on flowing current to produce a magnetic field?

electromagnet

Magnetism can be explained in terms of _____ spin patterns.

electron

Lodestone is a name for a naturally occurring magnetic material that is also called _____.

magnetite

The north magnetic pole of a compass needle is attracted to the _____ magnetic pole of the earth.

south