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