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## Physics library

### Course: Physics library>Unit 18

Lesson 5: Discovery of electromagnetism

# Experiment: What's the shape of a magnetic field?

See drawing from Hans Christian Ørsted's lab notebook

### What Happened?

The electric charge passing through the wire seemed to create a magnetic field!
This was a discovery made by Hans Christian Ørsted in 1820.

### Question: What is the shape of this field?

When this was first discovered (1819) it was assumed that it might be traveling along the wire:
Or maybe it is radiating outwards?

### Challenge: Find Proof!

Can you disprove these initial assumptions using a wire, a compass and a battery?
Here is an actual page from Ørsted's laboratory notebook contains sketches of the experiments he performed in July 1820.
Here he clearly shows that he repeatedly carried out the experiment with the conducting wire to the West and to the East of the magnetic needle (upper drawings), before putting the wire exactly over the magnetic needle.

## Want to join the conversation?

• If you turn on the switch to operate a lamp, and the lamp has no light bulb, does it consume any electricity?
• No electricity is consumed, because there is no complete circuit enabling electricity to pass.
• How do I read my electric meter?
• Which way does the
"electricity" really flow?
• Electric current is measured using what device?