Relevant Resource questions :

Concepts demonstrated :

• Current produces a magnetic field
• thermocouple

Equipment needed :

• 5kg apparatus
• bunsen burner
• beaker of ice water
• CCD camera (optional)

• Place the downward metal rod into the beaker of ice water.
• Heat the horizontal rod using the bunsen burner.

Physics involved :

The thermocouple creates an electric current which then produces a magnetic field. The magnetic field is then strong enough to raise the 5 kg weight.

How to use the Demonstration :

• Show the demonstration before any heating or cooling is done.
• Raise the top of the weight and show that it is separate from the body.
• Ask the students what they think will happen when the vertical rod is placed in ice water and the horizontal rod is heated.
• Perform the demonstration showing that the mass will be picked up.
• Ask the students to explain why they think the mass could be picked up.

• Thermocouple used to measure temperature.

• Make a poster describing the experiment - explain how current is generated and where this current flows.