Question

For the assertion A and the reason R given below, choose the correct alternative: A — Copper is used to make electric wires.
R — Copper has very low electric resistance.

• A. A is true, R is false.
• B. A is false, R is true.
• C. Both A and R are true, and R is not the correct explanation of A.
• D. Both A and R are true, and R is the correct explanation of A.

Hint:

In assertion-reason questions, if the reason provides the direct scientific or logical basis for the assertion, and both are factually correct, then the answer is the option where R correctly explains A.

Answer 1

The Correct Option is D

Step 1: Check the truth of the Assertion (A).
Copper is indeed used to make electric wires in household wiring, appliances, and transmission lines because of its high electrical conductivity and ductility.
Thus, A is true.
Step 2: Check the truth of the Reason (R).
Copper’s electrical resistivity is very low (\(\rho \approx 1.68 \times 10^{-8}\,\Omega\text{m}\) at \(20^\circ\)C), meaning it offers very little resistance to current flow.
Thus, R is true.
Step 3: Determine if R correctly explains A.
Electric wires need to conduct electricity efficiently with minimal energy loss. A low resistance material like copper allows maximum current flow with minimal heating, making it ideal for wiring.
Hence, R is the correct explanation for A.
\[ \boxed{\text{Both A and R are true, and R correctly explains A}} \]