North and South on a coil

The idea

Just like a magnet, an electromagnet has a North and a South pole, and its poles are reversed by reversing the direction of the current.

Two ends

A bar magnet has two poles, North and South. A coil with current behaves like a magnet.

How many poles do you think a coil with current has?

• Two
• One
• None

Reverse the current

Switch the current ON. Then press Reverse the current and watch the letters N and S.

The poles swapped

The end that was North became South, and the end that was South became North. Reversing the current reverses the poles.

Just like a magnet, an electromagnet has two poles, North and South. Its poles can be reversed by changing the direction of the current.

• Current | Left end of this coil | Right end of this coil
• One way | N | S
• Reversed | S | N

Notes

An electromagnet has two poles, North and South. Reverse the direction of the current and its poles are reversed.

Check yourself

An electromagnet has …

How can you reverse the poles of an electromagnet?

The North pole of an electromagnet is at its left end. The current is reversed. The North pole is now at its …

What does an electromagnet have in common with a magnet?

• only a North pole. Like a magnet, it has both a North pole and a South pole.
• a North pole and a South pole — correct. Yes!
• no poles. It has two poles, like a magnet.
• Use more cells. More cells change the strength. They do not swap the poles.
• Add more turns to the coil. More turns change the strength. They do not swap the poles.
• Change the direction of the current — correct. Yes!
• right end — correct. Yes!
• left end. Reversing the current reverses the poles, so it moves.
• both ends. A magnet has one North pole and one South pole.
• Poles that can never be reversed. The poles of an electromagnet can be reversed.
• Two poles, North and South — correct. Yes!
• It works without any current. An electromagnet behaves as a magnet only while current flows.