Which device converts chemical energy into electrical energy?

• A. Battery
• B. Transformer
• C. Capacitor
• D. Inductor

Answer: (A)

A battery is the device that converts chemical energy into electrical energy. Inside a battery, chemical reactions at the electrodes store energy as chemical potential. When the circuit is connected, these redox reactions push electrons through the external circuit, delivering electrical energy as current. The electrolyte simply carries ions to balance charge and keep the reactions going. This is different from the other devices: a transformer transfers existing electrical energy and changes voltage without creating energy from chemical sources; a capacitor stores energy as an electric field and is charged by an external source; an inductor stores energy in a magnetic field and likewise does not convert chemical energy. So the battery uniquely turns chemical energy into usable electrical energy.