As the coil rotates, the changing magnetic field induces a current in the wire. The direction of the current is given by Lenz's law, which states that the direction of the induced current is such that it opposes the change in magnetic flux. In this case, the induced current creates a magnetic field that opposes the external magnetic field, which slows down the rotation of the coil.
The amount of current induced in the coil is proportional to the rate of change of the magnetic flux. The faster the coil rotates, the more current is induced. The strength of the magnetic field also affects the amount of current induced, with a stronger magnetic field inducing more current. The number of turns in the coil also has an impact, with more turns leading to more current.
The emf induced in the coil is given by the equation:
```
emf = -N dΦ/dt
```
Where:
* emf is the electromotive force in volts
* N is the number of turns in the coil
* Φ is the magnetic flux in webers
* t is the time in seconds
The emf induced in the coil can be used to power a variety of devices, such as generators and motors. In a generator, the mechanical energy of the rotating coil is converted into electrical energy. In a motor, the electrical energy from the coil is converted into mechanical energy, causing the coil to rotate.
