Conductors and insulators are the two broad categories into which almost all matter is classified on the basis of their behaviour towards electrical current. It is very necessary for us to understand the electrical properties of substances because it helps us in the design of various electrical circuits and appliances. The effectiveness of a device depends largely on the type of material used.

Conductor

A conductor is a material which allows current to flow easily through it. Every metal is essentially a conductor. At the atomic level, we can say that a conductor is a material which has a large number of free electrons. These free electrons can move through the material and are responsible for the current flow.

A metal rod brushed with wool in the hand shows no signs of charging. A metal stick with a wooden or plastic handle shows symptoms of charging if wool is rubbed without touching the metal part.

Examples of Conductors

Conductors are used to make wires which carry electrical current. The wires that carry electricity to our homes and the various devices that we use are made of metal. Metals are good conductors of electricity and heat but also there are some non-metallic elements which conduct electricity. Human body is also a good conductor of electricity, and current can flow through our body and give us a shock.

There are many good conductors, some of which are given here.

1. Silver
2. Copper 
3. Gold 
4. Graphite 
5. Mercury
6. Saltwater

Properties of Electrical Conductor

There are many properties of electrical conductors which are given here.

1. Resistance (conductors have low resistance)
2. Inductance
3. Inside a conductor, the charge density is zero.
4. Inside a conductor, the electric field is zero.
5. Free charge exists on the surface of the conductor.
6. At the surface of the conductor, the electric field is normal to the surface of the conductor.

Uses or Applications of Conductors

There are many uses of conductors and some of them are given here.

1. Mercury is a frequent component of thermometers which is used to measure the temperature of the body.
2. Aluminium is used in the production of foil which is used for food-storage. It is also used to make fry pans which hold the heat for a long time.
3. Iron is a typical heat-conducting material which is used in the production of car engines.
4. Conductors are also used in automobile radiators for transferring the heat away from the engine.

Types of Conductors

There are four types of conductors which are given here.

1. Good conductor
2. Semiconductor
3. Resistors
4. Insulators

Semiconductors

Semiconductors are the materials that are sensitive to electricity between conductors and insulators. Therefore, semiconductors are non – metals which have limited electrical conductivity. In their pure form, some non-metals such as silicon and germanium are good semiconductors. By adding some impurities to them, their conductivity can be changed through a process called doping. Almost all electrical and electronic appliances use semiconductors to control the flow of electricity within them.

Resistors

A resistor is a small electronic apparatus that resists and reduces electric current and provides supply to electrical or electronic equipment in a controlled manner. By the resistance that the resistors offer, it protects the equipment from damage which can result from excessive energy input of electricity.

Insulator

Insulators are the materials or substances that resist or do not allow the flow of current through them. Generally, the insulators are solid. In addition, insulators are used in a variety of systems. Since they do not allow the heat to flow through them. The property that distinguishes insulators from conductors is their resistivity.

Examples of Insulators

There are many examples of insulators and some of them are given here.

1. Glass (best insulator and has high resistivity)
2. Plastic
3. Wood
4. Rubber (used in the production of tyres)

Properties of Insulators

There are many properties of insulators which are given here.

1. Resistance (insulators have high resistance)
2. Breakdown voltage (conduct electricity at high voltage)

Uses or Applications of Insulators

There are many uses of insulators and some of them are given here.

1. Thermal insulators prevent heat from migrating from one place to another. That’s why we use them to make thermoplastic bottles. They are also used to protect ceilings and walls from fire. 
2. Sound insulators help to control noise levels as they have good sound absorption ability. That’s why we use sound insulators in buildings and conference rooms so that they don’t generate noise. 
3. Electrical insulators oppose the flow of electrons or the passage of electricity through them. Therefore, we often use them in circuit boards and high voltage systems. Electrical insulators are also used in coating of electrical cables. and wires

Difference Between Conductors and Insulators

The important differences between conductors and insulators are given here.

1. Resistance of the conductor is low but it is high for the insulator.
2. Conductivity of the conductor is high but it is low for the insulator.
3. The Resistance of a conductor is low but it is high for an insulator.
4. Current can easily flow through the conductors but the insulator does not allow the current to flow through them easily. 

Conclusion

A conductor is a material which allows current to flow easily through it. Every metal is essentially a conductor.

There are many good conductors, some of which are given here.

1. Silver
2. Copper 
3. Gold 

Mercury is a frequent component of thermometers which is used to measure the temperature of the body.

There are four types of conductors which are given here.

1. Good conductor
2. Semiconductor
3. Resistors
4. Insulators

Insulators are the materials or substances that resist or do not allow the flow of current through them.

Resistance of the insulators is high.

Resistance of the conductor is low but it is high for the insulator.

Conductivity of the conductor is high but it is low for the insulator.