Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

Which of the following is an example of a device that converts electrical energy into mechanical energy?

1. Transistor

2. Generator

3. Audio loudspeaker

4. Inductor

The correct answer is: Audio loudspeaker

The audio loudspeaker is an example of a device that converts electrical energy into mechanical energy because it operates by using electrical signals to create sound waves. In a loudspeaker, electrical audio signals are fed into a coil of wire (the voice coil) that is situated within a magnetic field. The interaction between the magnetic field and the current flowing through the coil generates a force that causes the coil and the attached diaphragm to move back and forth. This movement produces vibrations in the air, which we perceive as sound. In contrast, the other options relate to different functions of electrical devices. A transistor is typically used for switching or amplifying electrical signals, while a generator converts mechanical energy into electrical energy. An inductor is a passive electronic component that stores energy in a magnetic field when electrical current passes through it. Therefore, the audio loudspeaker stands out as the device that effectively transforms electrical energy into mechanical energy for sound production.