Magnetism and Electromagnetism

Flashcards about magnets and electromagnetism.

Name four magnetic materials.

Iron, nickel, cobalt, and steel

What is a magnetic pole?

An area close to each end of a magnet.

What is the rule of magnetic poles?

Like poles repel, opposite poles attract.

What kind of materials can a magnet attract?

A magnet can only attract certain kinds of metal called magnetic materials.

How to test for magnetic materials?

By bringing a magnet close to the sample object. If they are attracted to each other, then the object is magnetic. If they can also repel each other, then the object is a magnet.

What is a magnetic domain?

A group of atoms that act like tiny magnets with a north and south pole.

Why does normal magnetic material not act like a magnet?

Domains pointing in different directions cancel each other out.

How can an iron nail be magnetized?

By stroking it with a permanent magnet.

How can a magnetic material be demagnetized?

Striking it with a hammer.

Give some uses for magnets.

Fridge magnets, maglev trains, sorting recycling, compasses, electromagnets.

What is a magnetic field?

The space around a magnet in which the magnetic force has an effect.

How can a magnetic field be shown?

Using iron filings or plotting compasses.

Which pole is the geographic north pole?

The geographic north pole is a magnetic south pole.

What is a solenoid?

A coil of wire wrapped around a core that becomes magnetic when electricity is turned on.

How can an electromagnet be made stronger?

Wrapping the coil around an iron core, adding more turns to the coil, and increasing the current flowing through the coil.

How can the magnetism of an electromagnet be turned on and off?

The magnetism of electromagnets can be turned on and off by closing or opening the switch.

What are reed switches?

They are activated by a magnetic field, causing the switch to close, completing the electric circuit.

What is a relay made of?

An electromagnetic coil and a magnetic switch.

What happen if a current flows through a coil?

Current flows through a coil, a magnetic field is produced, this can attract a switch in a seperate circuit, causing it to flow and allowing a current to pass through the circuit