Motors and Generators > Generating Voltage
The relative motion between a conductor and magnetic field is used to generate an electrical voltage
Students learn to:
- outline Michael Faraday’s discovery of the generation of an electric current by a moving magnet
- define magnetic field strength B as magnetic flux density
- describe the concept of magnetic flux in terms of magnetic flux density and surface area
- describe generated potential difference as the rate of change of magnetic flux through a circuit
- account for Lenz’s Law in terms of conservation of energy and relate it to the production of back emf in motors
- explain that, in electric motors, back emf opposes the supply emf
- explain the production of eddy currents in terms of Lenz’s Law
Students:
- perform an investigation to model the generation of an electric current by moving a magnet in a coil or a coil near a magnet
- plan, choose equipment or resources for, and perform a first-hand investigation to predict and verify the effect on a generated electric current when:
- gather, analyse and present information to explain how induction is used in cooktops in electric ranges
- gather secondary information to identify how eddy currents have been utilised in electromagnetic braking
Extract from Physics Stage 6 Syllabus (Amended October 2002). © 2009, Board of Studies NSW.