Introduction to Magnetism
A paper clip is pulled toward a bar magnet, but a plastic ruler is not. What property of the paper clip causes this?
It contains iron, which is attracted by magnetic forces.
What happens when the north pole of one magnet is brought close to the south pole of another magnet?
They attract each other.
What do magnetic field lines show around a magnet?
The direction and strength of the magnetic force.
What part of Earth causes it to behave like a giant magnet?
The liquid iron in Earth’s core.
What happens to the magnetic field around a wire when an electric current flows through it?
A circular magnetic field forms around the wire.
Why is magnetism described as an invisible, on-contact force?
Because magnetic forces cannot be seen and act when objects are close or touching.
What happens if two north poles are pushed together?
They repel each other.
Where is the magnetic field strongest on a bar magnet, and how do you know?
At the poles, where field lines are closest together.
Why does a compass needle move when placed on Earth’s surface?
Because it aligns with Earth’s magnetic field.
How does increasing the electric current in a wire affect the magnetic field?
It makes the magnetic field stronger.
A magnet attracts iron nails but not wooden sticks. What does this show about magnetic materials?
Only certain materials like iron are magnetic.
How can you identify the poles of a magnet using another magnet?
By observing attraction and repulsion between poles.
Describe the direction of magnetic field lines around a bar magnet.
They flow from the north pole to the south pole.
Where is Earth’s magnetic field strongest, and what are these areas called?
At the North and South Poles.
Using the right-hand grip rule, what does your thumb represent?
The direction of the current.
Explain why aluminum foil is not attracted to a magnet even though it is metal.
Because it does not contain iron or magnetic domains.
Why can you never isolate a single magnetic pole?
Because magnets always have both a north and south pole.
What does it mean if magnetic field lines are far apart in a diagram?
The magnetic field is weak in that area.
Why is Earth able to act like a giant magnet?
Because it has moving liquid iron in its core.
What happens to the magnetic field strength when you move closer to a current-carrying wire?
The magnetic field becomes stronger.
Explain how magnetism is a physical property of matter using an example.
Some materials like iron naturally respond to magnetic forces.
A magnet is broken in half. What happens to the poles of each piece?
Each piece forms its own north and south pole.
How would you show the magnetic field pattern of a bar magnet using iron filings?
The filings line up along the magnetic field lines, showing the pattern.
Why does a compass point north even when no magnets are nearby?
Because it aligns with Earth’s magnetic field.
Explain why increasing current or adding coils makes an electromagnet stronger.
Both increase the strength of the magnetic field produced.