Students will be able to
- recognize that a changing magnetic field will induce a current in a loop of wire,
- recognize that a more rapidly changing magnetic field will induce a greater current,
- recognize that a changing magnetic field can be achieved by moving a bar magnet toward or away from a wire,
- recognize that it is the relative motion of a bar magnet and a wire that achieves the changing magnetic field,
- state what a solenoid is,
- recognize that for a solenoid, the potential difference across its ends produced by a changing magnetic field can be increased by increasing the number of turns in the solenoid,
- recognize that an induced magnetic field always opposes that which induced it (Lenz’s law),
- recognize that for a straight wire moving through a magnetic field, a potential difference will only be induced across it if it is not moving parallel or antiparallel to the field,
- recognize that for a straight wire moving through a magnetic field, the potential difference induced across it will be at a maximum if it is moving perpendicular to the field,
- relate diagrams showing the motion of a wire in a magnetic field to graphs of the potential difference across the wire against time.
Students should already be familiar with
- potential difference,
- bar magnets,
- magnetic fields,
- magnetic field lines.
Students will not cover
- mathematical calculations of induced currents and potential differences,
- electric motors.