Question

The INCORRECT statement is

• A. Nickel is ferromagnetic and Aluminium is paramagnetic
• B. Cobalt is ferromagnetic and calcium is paramagnetic
• C. Nickel is ferromagnetic and cobalt is paramagnetic
• D. Both iron and cobalt are ferromagnetic

Hint:

Always remember "Fe-Co-Ni" (Iron, Cobalt, Nickel) as the three standard ferromagnetic elements. Any option labeling one of these as paramagnetic or diamagnetic is false.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Materials are classified magnetically into diamagnetic, paramagnetic, and ferromagnetic based on how they respond to external magnetic fields. We must identify standard elemental categorizations.
Step 2: Key Formula or Approach:
Recall theoretical facts about elemental magnetism:
Ferromagnetic materials: Iron (Fe), Cobalt (Co), Nickel (Ni).
Paramagnetic materials: Aluminium, Calcium, Oxygen, Platinum.
Diamagnetic materials: Copper, Lead, Water, Bismuth, Gold.
Step 3: Detailed Explanation:
Let's analyze each statement:
(A) Nickel is ferromagnetic (True), Aluminium is paramagnetic (True). Statement is True.
(B) Cobalt is ferromagnetic (True), Calcium is paramagnetic (True). Statement is True.
(C) Nickel is ferromagnetic (True), Cobalt is paramagnetic (False - Cobalt is strongly ferromagnetic). Statement is INCORRECT.
(D) Both iron and cobalt are ferromagnetic (True). Statement is True.
(E) Both copper and lead are diamagnetic (True). Statement is True.
Step 4: Final Answer:
The INCORRECT statement is (C).