Answer: Plastic is an insulator.
The other materials like conductors and semi-conductors conduct electric current more easily than insulators. There is no perfect insulator because they contain small numbers of mobile charges which can carry current. The phenomenon of the breakdown voltage of an insulator can make current flow through it when a sufficiently large voltage is applied to the electric field.
Properties of an Insulator
Following are the important properties of insulators:
They have a high air permeability since the air itself is a good insulator.
The outer electrons are tightly held together.
High mechanical strength.
High di-electric strength, etc.
Uses of Insulator
The insulators are used for the following purpose:
The coating of an insulator is often applied to electric wire and cable.
In the manufacturing of printed circuit boards, transistors, and ICs.
In a high voltage transformer, liquid insulator oil is used, etc.
Which one of the following is an Insulator?
Plastic is an insulator. It does not conduct electricity because electrons in them cannot move freely.