Question

Given below are two statements: Assertion (A): All metals are good conductors of electricity. Reason (R): Metals contain free electrons that allow electric current to pass. Choose the most appropriate answer.

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A).
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A).
• C. (A) is correct but (R) is not correct.
• D. (A) is not correct but (R) is correct.

Hint:

Metals conduct electricity because they have mobile free electrons.

Answer 1

The Correct Option is D

Step 1: Understanding the Question:

• We must judge the Assertion (A) and the Reason (R) separately and then decide whether R explains A.

Step 2: Detailed Explanation:

• Reason (R): Metals contain free (delocalised) electrons that carry the current. This statement is correct.

• Assertion (A): The statement is made for all metals. Metals differ widely in conductivity; for example lead and bismuth are comparatively poor conductors, unlike copper and silver. So the general statement in (A) is not correct.

• Therefore (A) is not correct but (R) is correct, which is Option (D), as given in the NTA final answer key.

Step 3: Final Answer:

• The correct option is (D).