Which transducer converts electrical energy to heat energy?

• A. Heater
• B. Earphones & Speakers
• C. Lighting lamp
• D. Motor

Answer: (A)

The main idea being tested is how electrical energy is turned into heat. A heater is designed to convert electrical energy directly into thermal energy. It uses a resistive element where electrical energy is dissipated as heat (Joule heating), warming the surrounding environment or the substance in contact with it.

Earphones and speakers transform electrical energy into sound through vibrating diaphragms. A lighting lamp primarily converts electrical energy into light (with some incidental heat as a byproduct). A motor converts electrical energy into mechanical energy, producing motion. So, for converting electrical energy into heat energy, the heater is the appropriate device.