Types of Insulators and Their Everyday Applications
Insulators are widely used in physics which is quite a contrast to the conductors. Usually, insulators refer to the material which doesn't allow electricity and to pass from it. These are known as insulators and also called bad conductors of electricity. We can find several examples in our daily routine for these insulators. Few examples like paper, glass, rubber, plastic, etc are known as insulators. Let's gain more knowledge about these insulators, types, etc.
The Reason Behind the Blockage of Electricity
As we know that the insulators cannot allow electricity to pass through them, the reason behind this is there is no sleep-free flow of electrons in the insulators. Electrons are fully packed and have very little scope for mobility and the free flow of electrons in insulators. Without moving an electron, electricity cannot be produced. But we can't say that there is a perfect insulator which can resist the passage of electricity. Because every insulator in science has a minimal number of free electrons. They produce negligible quantities of electricity.
Types of Insulators
There are five different types of insulators which are categorized by their capacity in producing electricity. They are -
Pin insulators
Suspension insulators
Strain Insulators
Stay Insulators
Shackle Insulators
Pin Insulators:- the pin insulators are the first and foremost model developed by scientists. But still, these are in use, especially for power networks. These insulators are available in three different types - namely one partisan 2 part, three-part insulator. Based on the requirement and application of voltage, the model can be chosen. These can run 33 VK systems. These are also known as overhead insulators. In one part insulator, the design they used as the upper part can have rain and work continuously but the lower part reminds dry. Similarly the two parts, three-part pin insulators were designed with slight modifications. 11 kV, 33 kV, 66 KV systems were used respectively. If the user requires more than these voltages, post insulators were used which are having multiple raincoats or petticoats to run in parallel.
Suspension Insulators:- to sort out the limitations of pin and post insulators, like a heavyweight, increase in voltage, etc will be sorted out by developing the suspension insulators. These insulators are designed by suspending a disc. The user can increase the number of discs based on the level of voltage. Every disc can carry 11KV to 15 VK. These insulators are easy to carry. If any of the discs is repaired, it can be replaced easily,y and you need not worry about the whole insulator.
Strain Insulators:- strain insulators are replaced by suspension insulators to meet the requirement of continuing till the dead-end or to avoid obstacles like sharp edges or pins. The strain insulator was easy to use and required fewer discs compared to suspension insulators. So they reduce cost, save time, and avoid discontinuity.
Stay Insulators:- The insulators which can use stay wires are known as state insulators. These insulators are used generally for low voltages at a minimum height from the ground. The porcelain used in such a way that even the insulator has broken completely, The wire may not touch the ground at any cost.
Shackle Insulators:- The other name is called spool insulators. Earlier these insulators were used widely at the distribution networks for low voltages. But after the enhancement of underground cable distribution, these are not in demand. Another highlight of these is letters is they can be used either vertically or horizontally. Also, they can distribute evenly at heavy loads.
Besides these insulators, we have other types called thermal insulators and electrical insulators. The insulators which don't allow heat to pass through them are known as thermal insulators. In simple terms, these insulators are known as insulators of heat. For example, the air is a good insulator of heat. if the insulators do not allow electricity to pass through them, they are known as electrical insulators.
Conclusion
Insulator science provides an awareness of various materials which act as electrical insulators, thermal insulators, and also are good insulators and bad insulators, etc. Also, insulator science deals with various types of insulators in which all types have both positives and negatives.
FAQs on What Is an Insulator in Physics?
1. What is an insulator in Physics, and can you provide some common examples?
In Physics, an insulator is a material that does not allow electric current to flow through it easily. This is because the electrons in its atoms are tightly bound and cannot move freely. Insulators have a very high electrical resistivity. Common examples of insulators include:
Rubber
Glass
Plastic
Wood (dry)
Air
Porcelain
2. How do insulators differ from conductors and semiconductors?
Insulators, conductors, and semiconductors are primarily differentiated based on their ability to conduct electricity, which stems from their atomic structure and energy bands. Here’s a comparison:
Insulators: Have a large energy band gap between their valence and conduction bands. This makes it extremely difficult for electrons to jump to the conduction band and move freely, resulting in very low electrical conductivity.
Conductors: Have overlapping valence and conduction bands, meaning there is no energy gap. This allows a large number of free electrons to move easily, resulting in high electrical conductivity. Examples include copper and silver.
Semiconductors: Have a small, non-zero energy band gap. They act as insulators at absolute zero temperature but can conduct electricity when energy (like heat or light) is supplied, allowing some electrons to move. Examples include silicon and germanium.
3. Why are some materials insulators at the atomic level?
Materials are insulators at the atomic level due to their electron configuration and the resulting energy band structure. The outermost electrons, or valence electrons, in an insulator are very tightly bound to their individual atoms. A large amount of energy is required to free these electrons from their orbits. In terms of energy band theory, insulators have a fully occupied valence band and an empty conduction band, separated by a large forbidden energy gap (typically > 3 eV). Since electrons cannot easily gain enough energy to cross this gap, they cannot move through the material to conduct current.
4. What are some important practical applications of insulators?
The primary importance of insulators is safety and the control of electricity. Their ability to block electrical flow makes them essential in many applications:
Electrical Wiring: Plastic or rubber coatings on electrical wires prevent short circuits and protect users from electric shock.
Power Lines: Large ceramic or glass insulators (called suspension insulators) are used on utility poles to support high-voltage lines without letting the current flow to the pole.
Electronic Components: Insulating materials like mica and Teflon are used to separate conducting parts in capacitors and on circuit boards.
Safety Equipment: Handles of tools like screwdrivers and pliers are made of insulating materials to protect electricians.
5. What happens when an insulator is placed in an external electric field?
When an insulator (also known as a dielectric) is placed in an external electric field, it does not conduct current. Instead, its molecules undergo a phenomenon called polarization. The positive and negative charges within each atom or molecule shift slightly in opposite directions, creating tiny electric dipoles. These dipoles align with the external field and produce an internal electric field that opposes the external one. The net effect is a reduction in the overall electric field strength inside the material. This property is crucial for devices like capacitors.
6. Can an insulator ever conduct electricity? Explain the concept of dielectric breakdown.
Yes, an insulator can be forced to conduct electricity under extreme conditions. Every insulating material has a limit to the strength of the electric field it can withstand, known as its dielectric strength. If the external electric field applied across the insulator becomes stronger than this limit, the force on the electrons becomes so large that they are ripped away from their atoms. This sudden flow of freed electrons causes the insulator to behave like a conductor. This phenomenon is called dielectric breakdown, and it often leads to permanent damage to the material. A real-world example of this is lightning, where air (an insulator) breaks down under a massive voltage difference.
7. How is the insulating property of a material measured in Physics?
The insulating property of a material is quantified by its electrical resistivity (ρ). Resistivity is an intrinsic property that measures how strongly a material opposes the flow of electric current. A material with a very high resistivity is a good insulator, while a material with a low resistivity is a good conductor. The unit of resistivity is the ohm-meter (Ω·m). Insulators typically have resistivity values greater than 10¹⁰ Ω·m.
