We are surrounded by an endless number of materials; these may be iron, silver, aluminium, paper, wood, rubber, etc. These materials may have different colours, textures, properties, etc. But the most important classification among them is based on their conductivity. That classifies them as conductors and insulators.
It is interesting to think that we might have experienced electric shock many times whenever we came into contact with any open electric wire or any electronic appliance, but the same does not happen when we come into contact with any wooden or plastic surfaces. It is because metallic materials are good conductors, whereas wood is not a good conductor.
Conductor vs. insulator
Conductors and insulators are different materials, and the major distinction between them is that one (the conductor) allows the current to pass and the other (the insulator) does not. Materials like iron allow the current to pass through them, whereas wood doesn't. So if we connect a bulb with a metallic wire, it will glow, but if we try the same experiment with a material like cloth or wood, the bulb will not glow, which shows clearly the different properties of conductors and insulators.
Difference between conductor and insulator in tabular form
|Parameters of comparison||Conductor||Insulator|
|Meaning of conductor and insulator||Conductors are those materials that allow current and heat to pass through them; this property makes any material a conductor.||Insulators are those materials that resist the current passing through them, and this property makes a material an insulator.|
|Store energy||A conductor is a type of material that does not store energy when it is kept in a magnetic field.||An insulator is a material that stores energy when it is kept in a magnetic field.|
|Electric field||When we talk about conductors, the electric field does exist on the surface of the conductor, but it remains zero inside.||In the case of an insulator, their electric field doesn't exist which creates a distinction between conductor and Insulator|
|Electrons||In a conductor, electrons move freely, which allows the current or energy to pass through it.||But when we talk about the insulator, where electrons do not move freely, it gives it the property that it doesn't allow the energy to pass through it.|
|Heat allowance||The heat allowance, or the thermal conductivity in the case of the conductor, is much higher than that of the insulator, or is very high.||Thermal conductivity, or the heat allowance in the case of an insulator, is very low when we compare it with any of the conductors.|
|Example||The example of the conductor can be Mercury, aluminium, silver, brass, copper, gold, or any other material that allows energy to pass through it.||Examples of insulators can be glass, rubber, plastic, wood, clothing, etc.|
What is a conductor?
In the simplest terms, a conductor can be defined as any material that allows electricity to freely flow through it. This happens because any material having the property of being a conductor allows the electrons to move easily from one atom to the next. Also, it permits the conductivity of light or heat from a source to another. It must be noted that the potential of any conductor directly dependent upon the quantum of free electrons present in the outermost shell. Hence, the potential of the material can be said to be directly proportional to the quantum of free electrons
In the case of a conductor, when any electric charge is supplied, then it gets spread across the surface of that object. As a consequence, it allows the movement of electrons within that object. So, it is clear that electric conductors make electrical charges pass easily. This property of the conductor is known as "conductivity," which means to conduct electricity.
Application of the conductor
Various applications for conductors, which are discussed below.
- We might have needed
the medical expert to get our body temperature checked whenever we feel sick. In such situations, the temperature is checked through a thermometer, which contains mercury, which is an example of a conductor.
- We are also familiar with iron. It is a common material used to conduct heat and put it to various uses, for example, in manufacturing vehicle engines. In order to absorb heat, iron plates are also made based on the same property.
- Various types of iron, such as copper, brass, steel, and aluminium, are well-known as good conductors of electricity. This is the reason why we use them in making electric circuits, and they are also used in the wire.
- One important thing to note is that gases are not good conductors of energy, and it is because the particles in gases are not concentrated but far away, which doesn't allow them to conduct energy.
Properties of a conductor
- A conductor has the following property, which is discussed below:
- The electrons and ions present in a conductor are permitted to move, resulting in the flow of current.
- As we know, the electric field in a conductor is zero, and it allows electrons inside it to move.
- The charge density of a conductor is zero.
What is an insulator?
To simply understand, an insulator can be defined as those materials or any substances that resist or don’t allow the free flow or movement of current or heat through them. Insulators are generally solid by nature. The electrons in an insulator do not move freely. Additionally, it has very high resistivity, which doesn't allow the current to pass or move freely. So the major property that distinguishes an insulator from a conductor is its resistance factor. Also, insulators can be used in numerous ways because they resist heat.
If any charge is applied to an insulator at any point on its surface, then that charge stays or remains on the same surface and doesn't spread across the surface. Metals such as aluminium, silver, gold, copper, and iron are very good conductors. It is because they allow the flow of electrons from one atom to another.
Application of insulators can be:
Akin to conductors Insulators also have various uses, although they cannot transmit current.
- The first is a thermal insulator. Thermal insulators disallow heat to move by resisting its movement from one place to another. Hence, we commonly use them to make thermoplastic bottles. Their use is also found in making walls and ceilings fireproof.
- Nowadays, noise pollution is very common, and various sound insulators are used to control the level of noise, or they are used as tools for noise cancellation because they are good insulators and absorb the sound. So, they are used in offices, conference halls, and buildings to make them quiet.
- One more prominent application of insulators is that they are used to coat electrical wires and large cables that transmit high-voltage current. They are good materials to cover the electric wires because insulators hinder and resist the passage of current through them.
- Rubber is also a very good insulator, which is why it is used to make rubber gloves that can be used to handle electric work or repair work. Also, slippers are made up of rubber, which also works as a good resistor to disconnect us from the earth's surface.
- The forbidden gap also distinguishes a conductor from an insulator, as it is found that there is no forbidden gap in a conductor whereas there is a forbidden gap in an insulator. A forbidden gap is that gap that exists between the conduction band and valence band. It helps to determine the conductivity of any material. Here, if the gap is not big, then the electron can move easily from the conduction band to the valence band, and hence the material is said to be a conductor. On the other hand, if the gap between the conduction band and the valence band is large, then the material is said to be an insulator.
Main Differences Between Conductor and Insulator (in Points)
- The heat allowance, also known as the thermal conductivity, in the case of the conductor is higher in comparison to the insulator, but the thermal conductivity or the heat allowance in the case of an insulator is very low when we compare it with any of the conductors.
- The simplest difference between a conductor and an insulator that can be noted is that a conductor is all those materials that allow current and heat to pass through themselves, and this property makes any material to behave like a conductor, whereas an insulator is all those materials that resist the current from passing through themselves, and this property makes a material behave like an insulator.
- The conductors are commonly used for making the outer coat of electrical wires, which needs to be good insulation. This helps to disconnect the inner material of a wire carrying current from the upper coating.
- Another important property of a conductor is that it is a type of material that does not store energy when it is kept in a magnetic field. On the other hand, an insulator is a material that stores energy when it is kept in a magnetic field.
- In the case of a conductor, its conduction band is full of many electrons, whereas the conduction band in the case of an insulator is empty.
- Conductor and insulator are also differentiated on the basis of the electric field because the electric field does exist on the surface of the conductor but remains zero inside, and in the case of an insulator, the electric field doesn’t exist.
- A conductor allows the current to pass through it because it has a large number of electrons moving freely, whereas an insulator does not have a freely moving large number of electrons.
- In a conductor, there are electrons that move freely, which allows the current or energy to pass through it. When we talk about the insulator, the electrons do not move freely, which gives it the property that it doesn't allow the energy to pass through it.
- Covalent bonds are chemical bonds, and these covalent bonds between the atoms of an insulator are strong whereas in the conductor the covalent bonds are weak.
- One more important difference is that when we place a conductor in a magnetic field, it does not store energy, whereas in the case of an insulator, it does.
- The example of a conductor can be mercury, aluminium, silver, brass, copper, gold, or any other material that allows energy to pass through it, and the examples of insulators can be glass, rubber, plastic, wood, clothing, etc. These are the materials that resist allowing energy to freely pass through them.
As we know, conductors are very important objects that help in various realms and offer a variety of applications. A conductor is very essential due to its property of allowing the flow of electricity and heat. So, materials made up of conductors have a variety of uses, and on the other hand, an insulator is a material that does not allow or resist the flow of current, resulting in various uses such as making rubber gloves to prevent electric shock, making thermal insulate, making rubber slippers to detach the contact from the earth, etc.
One more important thing is that we should also take into consideration the fact that, as per the International Annealed Copper Standard, silver is considered the most conductive material. But it is important to note that the cost of the silver is so high that it disqualifies it from being used in the process of making general wire. We have seen various properties of a conductor, such as that the electrons and ions present are permitted to move and result in the flow of current, the electric field in a conductor is zero, and it allows electrons inside it to move. Also, the charge density of a conductor is zero, among others. These pieces of evidence are sufficient to describe how the conductor is different from the insulator.