Two ends of a compass needle
A small magnet with a north and a south pole.
Two magnets meet
A compass needle is a small bar magnet. Its red end points towards north. You bring the north pole of a bar magnet close to that red end.
What will the two do?
What this lesson covers
The idea
A compass needle is a small bar magnet: its north-seeking end (north pole) points north and its south-seeking end (south pole) points south; like poles repel and unlike poles attract.
Two magnets meet
A compass needle is a small bar magnet. Its red end points towards north. You bring the north pole of a bar magnet close to that red end.
What will the two do?
- They push each other away
- They pull each other together
- Nothing happens between them
Try both poles
Choose which pole of the bar magnet faces the needle. See what the forces do.
North and south
The red end of the needle points to the north and is its north pole. The other end points to the south and is its south pole. Two north poles push each other away. A north pole and a south pole pull each other together.
A compass needle is a small bar magnet: its north-seeking end (north pole) points north and its south-seeking end (south pole) points south. Like poles repel and unlike poles attract.
Notes
A compass needle is a small bar magnet with a north pole and a south pole. Like poles repel, unlike poles attract.
Check yourself
What is a compass needle?
Which end of a compass needle is called its north pole?
The north pole of one magnet is brought near the south pole of another magnet. What happens?
The red (north) end of a compass needle is pulled towards one end of a bar magnet. That end of the bar magnet must be…
- A thin wire carrying a current. A wire carrying a current can deflect a compass needle, but the needle itself is a small bar magnet.
- A small piece of iron with no poles. A compass needle has a north pole and a south pole because it is a small bar magnet.
- A small bar magnet — correct. Yes!
- The end that points towards north — correct. Yes!
- The end that points towards south. The end that points towards south is the south seeking end, called the south pole.
- Both ends are north poles. A compass needle has one north pole and one south pole, one at each end.
- They repel each other. Unlike poles attract. It is like poles that repel.
- They attract each other — correct. Yes!
- They do not act on each other. Magnets act on each other with a force, and unlike poles attract.
- a north pole. A north pole would repel the red end, because like poles repel.
- a pole that cannot be told from this. Unlike poles attract, so a red end that is pulled towards a pole tells us that pole is a south pole.
- a south pole — correct. Yes!