What type of transducer converts mechanical energy into electrical energy?

A generator is the device that converts mechanical energy into electrical energy through the principle of electromagnetic induction. In a generator, mechanical energy, often derived from a rotating shaft powered by turbines or engines, is used to move a conductor, typically copper wire, through a magnetic field. This movement induces an electrical current in the conductor, effectively transforming the mechanical input into electrical output.

The other options represent different types of devices: a relay is used for switching an electrical circuit, a microphone converts sound waves (a form of acoustic energy) into electrical energy, and a transformer is designed to change the voltage level of alternating current in a circuit while transferring electrical energy from one circuit to another.