Which statement defines a cell?

• A. A device that stores chemical energy.
• B. A single connection between the plates and electrolyte which produces a specific voltage.
• C. A complete battery including multiple cells in series.
• D. An energy management device.

Answer: (B)

A cell is the basic electrochemical unit that converts chemical energy into electrical energy. It consists of two electrodes in an electrolyte and produces a specific voltage due to the chemical reactions occurring inside. The statement describing a single electrochemical unit with the electrodes and electrolyte that yields a defined voltage captures this idea, since a cell is the building block from which batteries are made and is defined by its ability to generate a voltage from internal reactions.

The other descriptions refer to larger or different concepts: a device that stores chemical energy aligns with a full battery or energy storage system, not a single cell; a complete battery includes multiple cells; and an energy management device is unrelated to the fundamental definition of a cell.