Question 1
Multiple choiceMedium1 markA sensor is powered by a hydrogen fuel cell supplied with hydrogen and oxygen. It ceases operating when its hydrogen supply is exhausted. Which paired description accounts for the energy conversion and distinguishes the cell from a primary cell?
Show answer and explanation
Answer: D. A fuel cell converts chemical energy directly to electrical energy. Its reactants are supplied continuously, whereas the reactants of a primary cell are contained within the cell.
A: incorrectly extends continuous external reactant supply to primary cells. B: inserts heat as an intermediate energy form; the reactant-supply distinction is correct. C: reverses the reactant arrangements of fuel cells and primary cells.