Magnet and wire interaction: Qualitative Testing Experiment

Aim

To test your model of magnet and current interactions

Prior Knowledge

• Newton's laws
• An understanding of what a scale reads
• A model of how a magnetic field exerts a force on moving charges

Description of the Experiment

A horizontal wire runs between the poles of a horseshoe magnet. The magnet is placed on the scale. Use your knowledge of Newton's laws and your understanding of how moving charges interact with a magnetic field to predict what will happen to the reading on the scale when the circuit is switched on.

Youtube movies can be stepped frame by frame using the , and . keys on your keyboard. If you want to download the movie to your computer, right-click or control-click HERE.

Youtube movies can be stepped frame by frame using the , and . keys on your keyboard. If you want to download the movie to your computer, right-click or control-click HERE.

Questions

• If you predicted the opposite of the actual outcome of the experiment, think carefully about the objects that are interacting with each other. When you used your hand rule, did you find the force exerted by the magnet on the wire or the force exerted by the wire on the magnet?
• Now draw two separate force diagrams, a force diagram for the wire and a force diagram for the magnet. Identify any Newton's third law pairs.
• Now think about: What does the scale read?