Match List-I (Types of cell/battery) with List-II (Applications)
| List-I | List-II |
| Types of cell/battery | Applications |
| (A) Leclanche cell | (I) Space Programme |
| (B) Mercury cell | (II) Automobiles and inverters |
| (C) Fuel cell | (III) Transistors/ clocks |
| (D) Lead storage battery | (IV) Hearing aids and watches |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
Commercial cells are of three kinds:
Primary cells (dry cell, mercury cell): the reaction happens only once, and the cell cannot be recharged.
Secondary cells (lead storage battery, nickel–cadmium cell): these can be recharged by passing current in the opposite direction.
Fuel cells: these convert the energy of combustion of a fuel, such as hydrogen, directly into electrical energy.
(A) Leclanche cell — This matches (III) Transistors/ clocks. This is the common dry cell: a zinc container as anode, a carbon rod as cathode, and a paste of \( \ce{NH4Cl} \) and \( \ce{ZnCl2} \). It gives about 1.5 V and is used in low-power devices such as transistors and clocks.
(B) Mercury cell — This matches (IV) Hearing aids and watches. It is small and gives a constant potential of about 1.35 V throughout its life, which suits low-current devices such as hearing aids and watches.
(C) Fuel cell — This matches (I) Space Programme. The \( \ce{H2-O2} \) fuel cell was used to supply electricity in the Apollo space programme, and the water it produced was used by the astronauts.
(D) Lead storage battery — This matches (II) Automobiles and inverters. This rechargeable battery delivers large currents, so it is used in automobiles and inverters.
Shortcut: The pair (A)–(III) appears in Options (3) and (4), and (B)–(IV) then leaves only Option (3).