KEPS31: Investigate principles of electromagnetic induction (including Lenz’s Law) in solid metal rings and coils of wire

Curriculum Topics
Physics: Electromagnetism and induction
Physics: Linear motion and force
Physics: Gravity and motion

Description
Fundamental principles of electromagnetic induction are explored through a variety of focussed investigations. Students use inquiry methods of prediction, testing and reflection to build their conceptual knowledge of Lenz’s Law and its implications. Some of these include electromagnetic braking effects as well as motor and generator applications.

Principle
Faraday’s and Lenz’s Law describes the induction of an electromotive force in a conductor as a result of its intersection with a time varying magnetic field. If the conductor is a closed loop intersecting a magnetic field in such a way that the field threading through the loop is changing then a current known as an ‘Eddy Current’ will form in the loop. The ‘Eddy current’ will have a direction so that its associated magnetic field will oppose the change that is causing it.

Tasks
1. Investigate three different loops and their associated electromagnetic effects.
2. Investigate electromagnetic braking effects.
3. Investigate the induction of currents in coils and compare with the electromagnetic induction in a closed loop.

Ideas for Extended Investigations
1. Investigate electromagnetic braking effects for different coils of wire with variables such as: number turns, turn density, overlay of turns, diameter of coil and length.
2. Investigate principles of operation of devices such as: Electromagnetic Cannon and the “Shaky” torch (additional equipment required).
3. Investigate differences in electromagnetic braking between solid metal rings and coils of wire.

Last edited 22nd Aug 2018