Question

What materials are used along with paper for insulation?

(a) varnish

(b) glass

(c) synthetic resin

(d) varnish, glass, synthetic resin

The question was posed to me in an international level competition.

This is a very interesting question from Construction of Electromagnets topic in division Design of Electromagnets of Design of Electrical Machines

Answer 1

Right answer is (d) varnish, glass, synthetic resin

To explain: The insulation used in the electromagnets is paper. It is being insulated along with the varnish, glass and synthetic resin and treated into the form of sheets to form proper insulation.