Question

Why is plastic used in the covering of electrical appliances?
A.Good conductors of heat and electricity
B.Durable
C.Poor conductors of heat and electricity
D.None of the above

Answer 1

Hint: Plastics are very good insulators of both heat and electricity. Some plastics like thermosets can even work at high temperature conditions. Durable plastics means a plastic which can withstand high pressure conditions as at such extreme conditions other material may get broken.

Complete step by step answer:
Electricity is essential for us as it is a valuable and versatile servant but it is also potentially lethal or hazardous if not to be taken care of properly. Plastics do not conduct electricity as they are good insulators for electricity as therefore plastics are used in a variety of applications both in household and industrial purposes where their insulating properties are needed. PVC is widely used plastic which is used to insulate wiring, while thermosets which are highly good insulators and can withstand even at high temperature conditions, such thermosets are widely used for manufacture of switches, light fitting purposes and handles of hot equipment. Plastics are especially suited for material such as hairdryers, electric razor and food mixers as they protect the consumer from the risk of getting electric shock.
Also, plastics are a poor conductor of heat too. Equipment or appliances which get hot very high, in order to handle such equipment manufacturers made extensive use of plastics for the manufacturing of such goods. To further protect consumers, plastics can be made fire resistant through the use of special flame retardant additives.

Thus, the correct option is C.

Note:
Durable means a property to withstand high pressure or damage. Plastics are both oil resistant and acid resistant and also they do not corrode. But this property of plastics is not used in order to use as a covering of electrical appliances.