Why is a voltage produced when a coil spins?
When a coil spins, a voltage is induced in the coil due to a phenomenon called electromagnetic induction. This process occurs when there is a change in the magnetic field passing through the coil.
To understand this phenomenon, you need to be familiar with Faraday's law of electromagnetic induction, which states that a changing magnetic field induces an electromotive force (EMF) in a conductor, in this case, the coil.
Here's how a voltage is produced when a coil spins:
1. Magnetic field: When a magnetic field passes through a coil, the magnetic field lines effectively cut across the coil's turns. This causes a change in the magnetic field passing through the coil.
2. Change in magnetic field: As the coil spins, the orientation and strength of the magnetic field passing through the coil change. This change in the magnetic field induces a change in the magnetic flux through the coil.
3. Induced EMF: According to Faraday's law, the change in magnetic flux induces an electromotive force (EMF) in the coil. The induced EMF creates an electric current within the coil.
4. Voltage: The induced EMF generates a voltage across the coil's terminals. This voltage is proportional to the rate of change of the magnetic field passing through the coil and the number of turns in the coil.
In summary, when a coil spins, the changing magnetic field passing through it induces an electromotive force (EMF), which results in a voltage across the coil. This phenomenon, known as electromagnetic induction, is the fundamental principle behind devices like generators and electric motors.