Which of the following represents a diamagnetic material?

Diamagnetic materials are characterized by their tendency to be repelled by magnetic fields. This property arises due to the arrangement of electrons within the atoms of the material. In a diamagnetic material, all of the electrons are paired, which means that their magnetic moments cancel each other out, resulting in no net magnetic moment.

In the case of copper, it is classified as a diamagnetic material because its electron configuration results in all its electrons being paired. Thus, when exposed to a magnetic field, copper does not retain any magnetization, making it repel weakly from the magnetic field.

In contrast, materials like nickel, cobalt, and iron are ferromagnetic, meaning they have unpaired electrons that result in a net magnetic moment. This leads to a strong attraction to magnetic fields, which is why they behave differently than diamagnetic materials. Understanding the differences between these types of materials is crucial in fields such as material science, physics, and electrical engineering, where magnetic properties are important in various applications.