Which cell is used in automobiles and inverters?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Lead storage cell
Automobiles and inverters need a battery that gives a large current and can be recharged many times, that is, a secondary cell. The lead storage battery is such a cell. While it is in use:
\( \displaystyle \text{Anode: } \ce{Pb(s) + SO4^2-(aq) -> PbSO4(s) + 2e-} \)
\( \displaystyle \text{Cathode: } \ce{PbO2(s) + SO4^2-(aq) + 4H+(aq) + 2e- -> PbSO4(s) + 2H2O(l)} \)
\( \displaystyle \text{Cell reaction: } \ce{Pb(s) + PbO2(s) + 2H2SO4(aq) -> 2PbSO4(s) + 2H2O(l)} \)
On charging, these reactions are reversed. So the cell used in automobiles and inverters is the lead storage cell.
Why the other options are incorrect
Option (1) Mercury cell — Incorrect. It is a primary cell for low current devices such as hearing aids and watches; it cannot be recharged.
Option (2) Dry cell — Incorrect. The Leclanché dry cell, used in torches and clocks, is also a primary cell and gives only a small current.
Option (4) Fuel cell — Incorrect. A fuel cell turns the energy of combustion of a fuel such as hydrogen directly into electricity; it is used, for example, in spacecraft, not as a car battery.
NCERT (2026-27 edition):
Secondary Batteries
