Live Classroom 9/25 Electromagnets and Review

​

An electromagnet is an object that acts as a magnet when electricity passes through it.

Electromagnets generally produce stronger electric force than a standard magnet.

Electromagnets come in many sizes and shapes.

However, all electromagnets contain:

• power source

• copper wire

• iron core

Note that the wire wraps around the iron core. Coiling the wire causes the electromagnet to take on new properties.

​power
source

​copper
wire

​iron core

​



Electromagnets combine the properties of both electricity and magnetism.

Today and tomorrow, think about the ways that electricity and magnetism are related.

The wire coiled around the iron core of an electromagnet is called a solenoid.

Solenoids cause electromagnets to produce stronger magnetic fields than electromagnets without solenoids.

The more coils, or turns, in a solenoid, the stronger the magnetic force it will produce.

​

Solenoid

Activity and discussion:


Take out your compass and bar magnet or go to https://phet.colorado.edu/sims/html/magnet-and-compass/latest/magnet-and-compass_all.html

Move the compass close to the north pole (red) of your magnet.

In what direction is the north side of the needle on your compass pointing in relation to the magnet. Why?
Now move the compass to the south pole of your magnet (blue). What happens to the needle? Why?

• Force between charged particles and involves the transfer of electrons

Electric Force

• Attracted to certain metals and has two poles

​Magnetic Force

​Both: opposites attract, act across empty space, have two distinct areas (poles and charges), use field lines to model