A bar magnet sits alone on a shelf, touching nothing. Is there a magnetic field around it?
Hold a magnet a short distance from a steel paperclip on a desk. The paperclip jumps the gap and clicks onto the magnet.
The last lesson showed that any magnet has a magnetic field around it. This lesson says what that field does to magnetic materials inside it.
Now consider the paperclip just before it jumped. It sat inside the magnet's magnetic field.
The paperclip is steel. Steel is a magnetic material: a kind of material a magnet acts on.
The paperclip never touched the magnet before it moved. The magnetic field already filled the space around the paperclip. The paperclip experienced a force: a pull toward the magnet.
No contact is needed, because the magnetic field already fills the space around the magnet. A steel bracket inside the field experiences a force. And a piece of nickel inside the field experiences a force too.
A steel screw rests inside a magnet's magnetic field, not touching the magnet. Does the screw experience a force?
Write down the fact:
In a magnetic field, any magnetic material will experience a force.
Steel is a magnetic material, and the screw sits inside the field.
Yes: the screw experiences a force.
A steel nail sits inside a magnetic field, touching nothing. Does it experience a force?
A magnet's field fills a toolbox. A steel bolt lies at the far side of the toolbox, inside the field. What does the bolt experience?
Write down the fact:
In a magnetic field, any magnetic material will experience a force.
The bolt is steel, and it lies inside the field, even at the far side of the toolbox.
The bolt experiences a force. No contact is needed.
That is why the paperclip jumped: it is a magnetic material, it sat inside a magnetic field, so it experienced a force.
A steel bolt lies inside a magnet's magnetic field, a hand's width from the magnet. Which statement is true?
A magnet pulls a steel tack across a tabletop before they touch. Why can the magnet act on the tack without contact?
A piece of nickel sits inside a magnetic field, far from the magnet but still inside the field. What does the nickel experience?