Correct Answer:
D. Mechanical
A generator is a device that converts one form of energy into electrical energy based on the principle of electromagnetic induction. Specifically, a generator requires an input of Mechanical energy to rotate coils of wire within a magnetic field. This rotation induces an electric current, thereby transforming the mechanical motion into electrical power.
- Heat energy is often an intermediate step (e.g., burning fuel to create steam to turn a turbine), but the generator itself performs the mechanical-to-electrical conversion.
- Chemical energy is converted into electrical energy in batteries.
- Solar energy is converted by photovoltaic cells (solar panels) directly into electrical energy, or indirectly via thermal processes that still drive a mechanical turbine.