Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Copper is used to make electrical wires.
Reason R: Copper has very low electrical resistance.
In the light of the above statements, choose the correct answer from the options given below.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Both A and R are true and R is the correct explanation of A
Assertion A — True. Copper is the metal most widely used for household and power wiring, in electric cables, motors and transformers.
Reason R — True. Copper has a very low resistivity, about \(1.7\times10^{-8}\,\Omega\,\mathrm{m}\), next only to silver among common metals; it is one of the best conductors of electricity.
Does R explain A? Yes. A wire should carry current with as little loss as possible; the heat lost in a wire grows with its resistance, so a low-resistance metal wastes little energy and does not heat up. That is why copper is chosen; silver is slightly better but far too costly, and copper is also easily drawn into wires.