Why is electrical wiring usually made from copper and not silver?
a) Copper is less expensive
b) Copper is a better conductor
c) Copper is a better insulator
d) Copper is non magnetic
Which of the following statements regarding an electromagnet is NOT true?
a) It is permanent magnet
b) It is used in fans and radio
c) Insulated wire is wound around it
d) It works only in the presence of electricity