Magnet, coil and galvanometer: magnitude of the current: Observational Experiment

Aim

To find a pattern between the magnitude and direction of the induced current in a coil and the velocity of the magnet.

Prior Knowledge

1. Deflection of a galvanometer and the direction of the current through it.
2. Electromagnetic induction

Description of the Experiment

Watch the experiment. Find a pattern in the motion of the magnet and the magnitude of the induced current. Find a pattern in the motion of the magnet and the direction of the induced current.

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

1. For each of the experiments draw a picture representing the direction of the magnetic field of the magnet and the direction of the current in the coil.
2. Add the direction of the magnetic field created by the current in the coil to your picture.
3. Indicate whether the external magnetic field through the coil is increasing or decreasing in each experiment.
4. Describe a pattern that you find in the pictures.
5. How does the magnitude of the induced current depend on the speed of the magnet?
6. Why do you think the magnitude of the current is larger when the magnet is moving faster? When answering this question talk about the changes in the external magnetic field through the area of the coil.