Slide a magnet along the underside of a lunch table. On the tabletop, a steel pin slides along above it. The magnet never touches the pin. Something acts across the gap.
In earlier grades you saw that magnets push and pull on each other without touching. This lesson names what fills the space around every magnet.
Sprinkle iron filings on a sheet of paper over a bar magnet. The filings snap into a pattern of arcs. The filings reveal something that was already there: the space around the magnet is not empty.
The magnet fills the space around it with a magnetic field.
Which field does every magnet have because it is a magnet?
The magnetic field is there even where nothing touches the magnet. A bar magnet sealed in an empty box still has a magnetic field around it. And a fridge magnet lying in a drawer still has a magnetic field around it.
The magnetic field is invisible. The filings only make its shape easy to see.
A magnet pins a photo to a steel filing cabinet. Where does the magnet's magnetic field exist?
Write down the fact:
Any magnet has a magnetic field around it.
The field fills all the space around the magnet, not just the spot touching the cabinet.
The magnetic field exists in all the space around the magnet.
Where does a magnet's magnetic field exist?
A toy magnet is sealed inside a plastic egg, touching nothing. Does it still have a magnetic field?
Write down the fact:
Any magnet has a magnetic field around it.
Nothing needs to be near the magnet: the field is there either way.
Yes: a magnetic field still surrounds the toy magnet.
That is what acted under the lunch table: the magnet's magnetic field fills the space between the magnet and the pin.
Which statement about a bar magnet's magnetic field is true?
A magnet holds a grocery list against a steel door through a sheet of paper. Why does the magnet's hold reach through the paper?
Which of the following has a magnetic field around it?