Diamagnetism and Hard Magnetic Materials – Rankers Physics

Magnetic Properties of Matter: Practice Problem & Solution

Assertion (A): The permanent magnetic moment of the atoms of a material is zero. The material must be diamagnetic. Reason (R): Hard magnetic materials have high retentivity, high coercivity and large hysteresis- loss and are suitable for permanent magnetism.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Magnetic Properties of Matter. Understanding the underlying formula is key to arriving at the correct answer below:

Diamagnetic materials are characterized by the absence of permanent atomic magnetic moments, making Assertion (A) true. Hard magnetic materials need high retentivity and coercivity for permanent magnetism, making Reason (R) true. However, the two statements describe different properties and are not causally related.

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