Final answer:
Increasing the area of the coil in a generator will not increase its voltage output; the induced emf in a coil is proportional to the rate of change of magnetic flux, which is affected by the frequency of rotation, not the coil's area.
Step-by-step explanation:
The element that will not increase a generator's voltage output is increasing the area of the coil. This is because the voltage output (or electromotive force, emf) of a generator is determined by Faraday's law of electromagnetic induction, which states that the induced emf in a coil is proportional to the rate of change of magnetic flux through the coil. Rotating the generator faster increases the rate of change of magnetic flux, and therefore increases the emf. On the contrary, simply increasing the area of the coil without a change in the magnetic field strength or the rate of change of the magnetic flux does not increase the induced emf.
In summary, increasing the area of the coil does not influence the voltage output of a generator because the critical factor is the rate of change of flux, which is not affected by the area of the coil when it is stationary. Instead, increasing the frequency of rotation or the number of turns in the coil would lead to a higher emf and, consequently, a higher voltage output.