Magnetsm I - SS3 Physics Past Questions and Answers - page 2

Magnetic fields are regions in space around a magnet or a current-carrying conductor where magnetic forces are exerted on magnetic materials. They are regions in space where magnetic forces are exerted on magnetic materials. The strength and direction of the magnetic field are determined by the strength and direction of the current flow or magnetization.

Magnetic forces are exerted on magnetic materials in the presence of magnetic fields. Like charges repel each other, and opposite charges attract each other. Similarly, like magnetic poles repel each other, and opposite magnetic poles attract each other. The force between two magnetic poles is proportional to the product of their pole strengths and inversely proportional to the square of the distance between them.

Ferromagnetism is a property of materials that have a strong magnetic response in the presence of an external magnetic field. These materials, such as iron, nickel, and cobalt, have a large magnetic moment due to the alignment of their electron spins.

Diamagnetism, on the other hand, is a property of materials that have a weak magnetic response in the presence of an external magnetic field. These materials have all of their electron spins paired and therefore have no net magnetic moment. Paramagnetism is a property of materials that have a weak magnetic response in the absence of an external magnetic field but have a strong magnetic response in the presence of an external magnetic field. These materials have some unpaired electron spins, which cause a net magnetic moment.