Electromagnetic induction
A magnet and a coil of wire can be used to produce an electric current. A The potential difference across a cell, electrical supply or electrical component. It is measured in volts (V). is produced when a magnet moves into a coil of wire. This process is called The production of a potential difference (voltage) when a conductor, such as a wire, is moved through a magnetic field or exposed to a varying magnetic field. If the conductor is part of an electric circuit, an induced current will flow.. The direction of the induced voltage is reversed when the magnet is moved out of the coil again. It can also be reversed if the other pole of the magnet is moved into the coil.
If the coil is part of a complete circuit, then a current will be induced in the circuit.
Notice that no voltage is induced when the magnet is not moving, even if it is inside the coil.
To increase the induced voltage:
- move the magnet faster
- add more turns to the coil
- increase the strength of the magnet
Image caption, 1. A bar magnet rests outside a wire coil connected to an ammeter showing no current
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