The number of turns of a coil of wire can directly affect the magnitude of the induced electromotive force (EMF) according to Faraday's law of electromagnetic induction. Faraday's law states that the magnitude of the induced EMF is directly proportional to the rate of change of magnetic flux through the coil.
The magnetic flux through a coil is determined by the magnetic field strength and the area enclosed by the coil. The more turns a coil has, the larger the area enclosed by the coil, and therefore, the greater the magnetic flux. When the magnetic flux changes, an EMF is induced in the coil.
Mathematically, the relationship between the number of turns (N) and the induced EMF (E) can be expressed as:
E ∝ N
This equation shows that the induced EMF is directly proportional to the number of turns of the coil. In other words, doubling the number of turns will double the induced EMF, while halving the number of turns will halve the induced EMF.
It's important to note that this relationship assumes that other factors, such as the magnetic field strength and the rate of change of magnetic flux, remain constant. In practical applications, factors such as the resistance of the coil and the external circuit can also influence the actual voltage measured across the coil.