Electromagnetism
Induced voltage
- A The potential difference across a cell, electrical supply or electrical component. It is measured in volts (V). will be induced (generated) in a wire when the wire is moved between the poles of a magnet.
- If the wire forms part of a complete circuit, this induced voltage will cause a current.
- The induced voltage can be made greater if the wire is formed into a coil.
Look at the meter readings in the following images.
Step one
Magnet with a wire wrapped around it. The meter reading is zero
Step two
Magnet moves from north to south through wire, meter reading is now positive
Step three
Wire wrapped around all of magnet, meter reading is zero
Step four
Magnet moves from south to north through wire, meter reading is now negative
The voltage is induced and so the current is generated, only when the magnet and the wire (coil) move relative to each other. This is because a A material which allows charge to move easily through it. must cut across magnetic field lines for a voltage to be induced.
