Understanding Molecular Magnets and Properties

What is the relative permeability of a material?

• It is the ratio of the material's magnetic field strength to the electric field strength.

• It is the ratio of the material's magnetic permeability to the permeability of free space.

• It is the measure of a material's ability to conduct electricity.

• It is the measure of a material's resistance to deformation.

Which of the following best describes the loss of magnetisation in a 'soft' magnetic material?

• It is the permanent loss of magnetisation due to high temperature.

• It is the temporary loss of magnetisation when the external magnetic field is removed.

• It is the loss of magnetisation due to mechanical stress.

• It is the loss of magnetisation due to chemical reactions.

What is magnetic saturation in a material?

• It is the point at which a material can no longer increase its magnetisation regardless of the increase in the external magnetic field.

• It is the point at which a material begins to lose its magnetisation.

• It is the point at which a material's magnetisation becomes zero.

• It is the point at which a material's magnetisation is equal to its electric field strength.

Which of the following materials is most likely to have a high relative permeability?

• Copper

• Air

• Iron

• Wood

Why are 'soft' magnetic materials preferred in the cores of transformers?

• They have high electrical resistance.

• They can be easily magnetised and demagnetised.

• They are lightweight and inexpensive.

• They have a high melting point.