Magnetism and electromagnetism

How do you construct an electromagnet

Pass current through a wire, coil wire around an iron core, becomes magnetic

How do you increase the strength of an electromagnet

Increase current, add more turns in wire

How does a motor work

Coil has current, this creates a magnetic field, this field interacts with the magnetic field of permanent magnets, this creates a force causing it to spin. Forces on opposite sides of the coil are in opposite directions, a commutator reverses the direction of current every half turn.

In the right hand rule, what does your thumb represent

Direction of current

What does a circle with a dot mean

Current is flowing out of the page

What does a circle with a cross mean

Current is flowing into the page

When the field lines are closer together, what does that say about the strength of the magnet

Higher

How does a loudspeaker work

a coil is wrapped around a permanent magnet and attached to a speaker cone. alternating current is flown through the coil, which creates a magnetic field that interacts with the field from the magnetic. motor effect means this makes a force, because it is constantly alternating, the coil oscillates making the speaker cone oscillate creating sound waves