Question

(i) Write two characteristics of a material used for making permanaent magnets.
(ii) Why is core of an electromagnet made of ferromagnetic materials ?

Answer 1

(i) The materials chosen to make permanent magnets should have
(ii) High retentivity so that the magnet is strong.
(b) High permeability so that the magnet can be magnetished easily.
(i) The core of electromagnets are made of ferromagnetic materials, which have high permeability and low retentivity. Soft iron is a suitable material for this purpose.