• Written By Shikha Pandey
  • Last Modified 25-01-2023

Charging by Friction: Learn Concept, Examples & More

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Charging by Friction: Charging by friction is an important topic in physics. Students need to pay close attention to each topic in Physics as they get tougher in higher classes. The electricity is caused by rubbing a woollen sweater against our bodies, which creates a charge imbalance. Electrons are transmitted from one body to another when two distinct insulating materials are rubbed together; this process is called Charging by Friction. 

With regular study and practice, students can master the subject. One topic that gets deep in higher studies is Friction electricity. It is very important to understand the topics like friction static electricity, friction conduction induction, static electricity charging by friction etc., for any physics students. The article covers all the details that one needs to know about Charging by Friction.

What is Charging by Friction: Friction Electricity

All matter is made of atoms, which consist of electrons, protons and neutrons. Electrons are negatively charged particles; protons are positively charged particles and neutrons carry no charge. Most of the objects in nature are not charged because the number of electrons in an object is equal to the number of protons, and this makes the object electrically neutral. In order to produce a charge on an object, we need to create an imbalance of electrons or protons in that object. This imbalance of electrons and protons can be easily created by rubbing two objects over one another. This process of charging is called charging by friction.

Charging by Friction

Friction Static Electricity: Static Electricity Charging by Friction

Students must understand important concepts like static electricity charging by friction, friction conduction induction, friction static electricity, etc.

When two objects are rubbed with each other, an imbalance of charged subatomic particles occurs between the two objects. Electrons are free to move from one place to another place, but protons do not move. So, when we rub two objects with each other, the electrons from one object get transferred to another object. The object which loses electrons becomes positively charged, and the object which gains electrons becomes negatively charged.

This transfer of electrons by rubbing two objects with each other generates static electricity or frictional electricity. Charges are quantized. The quantization of charge refers to the fact that all free charges are integral multiples of a basic unit of charge denote by \(‘e’\) and can be increased or decreased in steps of \(e\). Here, \(e\) represents the charge present on an electron, and it is numerically equal to \(1.6 \times {10^{ – 19}}\,{\rm{C}}\). Charges less than the charge of an electron cannot occur free in nature. This is the reason only integral multiple of charge of an electron can be transferred or gained by a body in the process of charging by friction.

CLEAR YOUR CONCEPTUAL DOUBTS ON FRICTIONAL CHARGE

The Behaviour of Electric Charge

There are two types of electric charges, namely positive charge and negative charge. Electrons carry a negative charge, and protons carry a positive charge. These charges are equal in magnitude but opposite in nature. When a positively charged body is brought close to a negatively charged body, then they attract each other, but if we bring two positively charged bodies or two negatively charged bodies towards each other, they will repel each other. Therefore, we can say that like charges repel each other and unlike charges attract each other.

Behaviour of Electric Charge
Behaviour of Electric Charge

Charging by Friction – Examples

  1. When an ebonite rod is rubbed with fur, the electrons from the fur get transferred to the ebonite rod. The ebonite rod acquires a negative charge due to the gain of electrons, and the fur becomes positively charged because it loses electrons.
  2. When rubbing Styrofoam with a paper, some electrons from the paper get transferred to the Styrofoam. Therefore, the Styrofoam acquires a net negative charge because it gains an excess of negatively charged particles, and the paper acquires a positive charge.
  3. When rubbing a plastic comb with dry hair, it acquires some charges, and it attracts tiny pieces of paper.
  4. When rubbing a glass rod with silk, the glass rod acquires a positive charge because it loses electrons, and the silk becomes negatively charged as it gains electrons.
Charging by Friction – Examples

Materials that can be Charged by Friction

Not all materials can be charged by friction. For example, metals are good conductors for electricity, so they cannot be charged by friction because electric charges are free to move inside metals. Non-conducting materials or insulators can be charged by friction because they do not allow added electrons or charges to move through them. These charges remain static and produce static electricity. Some materials that can be charged by friction are plastic scale and dry hair, plastic rod and cat’s fur, glass rod and silk cloth.

Practice Exam Questions

Triboelectric Series

Different materials show different tendencies to lose or gain electrons on rubbing. The arranged series of these materials depending upon their ability to hold or lose electrons, is called the triboelectric series. Some materials in the increasing order of their tendencies to lose electrons are given below.

Sulphur, rubber, brass, copper, ebonite, paraffin wax, silk, lead, cat’s fur, wool, glass, asbestos.

If we rub any two materials given in the list with each other, then the material which comes first in the list will gain electrons, and the material which comes later will have the tendency to lose electrons. For example, if we rub the glass with a silk cloth, the glass will lose electrons and acquires a positive charge, whereas silk will gain electrons and acquires a negative charge.

Charging by Friction, Conduction and Induction

We cannot create a charge. It can only be transferred from one body to another. The three methods to charge an object are as follows:

  1. Charging by friction: This is the process of charge two non-conducting bodies by rubbing them with each other vigorously. In this process, one body loses electrons, and the other body gains electrons. The object to which electrons are added acquires a negative charge, and the object which loses electrons acquires a positive charge because of the presence of extra protons.
  2. Charging by conduction: This is the process of charging an uncharged body by bringing it in contact with a charged body. Suppose we bring a neutral object in contact with a negatively charged body then some of the negatively charged electrons will get transferred to the neutral body and make it carry a net negative charge.
  3. Charging by induction: This is the process of charging a neutral body by bringing it near a charged body but not in contact. Suppose we want to provide a net positive charge to a neutral metal plate, then in this process, we will bring a negatively charged body near the neutral metal plate. This will accumulate positive charges in the neutral metal plate near the side which faces the charged body, and all the free electrons will accumulate on the opposite side. If we connect this side of the metal plate to the earth, then all the free electrons will move to the earth. Now, if we remove the earthing and the charged body, the bounded positive charge will redistribute themselves in the metal plate, and it will become positively charged.

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Charging by Friction: Conclusion

From this article, we can conclude that when two insulating objects rub over one another, they get charged. The movement of electrons from one object to another produces a net electric charge on an object. No object in nature is charged, but they do carry some charged particles in the form of electrons and protons. The number of electrons and protons are equal in an object, and this makes them electrically neutral. The imbalance of charge can be created by rubbing two objects with each other. Frictional electricity is produced by rubbing two objects.

PRACTICE QUESTIONS RELATED TO FRICTIONAL CHARGE

Frequently Asked Questions on Charging by Friction

We have provided some frequently asked questions about charging by friction here:

Q.1: What materials can be charged by friction?
Ans: Insulating materials are usually charged by friction because these materials do not allow electrons to move through them freely. Electrons are static on these materials. For example, wool, plastic, glass, ebonite and fur can be charged by friction.

Q.2: Does friction cause charge?
Ans: Yes, friction causes the production of charge on an object. When two objects rub against each other vigorously, the transfer of free electrons takes place between them. The object from which electrons rubbed off acquires a positive charge, whereas the object which gains electrons acquires a negative charge.

Q.3: What type of electricity is produced in the process of charging by friction?
Ans: Static electricity is produced in the process of charging by friction. It is also known as frictional electricity. Static electricity results from an imbalance of electric charges; it generally attracts light objects and produces crackling sounds and sparks.

Q.4: What is charging by friction?
Ans: Charging by friction is a method of developing a net charge on an electrically neutral body by rubbing it with another body. We can charge two insulating materials by rubbing them with each other vigorously. In the process of charging by friction, an object which loses electrons becomes positively charged, and the object which gains electrons becomes negatively charged.

Q.5: What are the \(3\) methods of charging?
Ans: The following are the \(3\) methods of charging an uncharged body:
a. Charging by friction
b. Charging by conduction
c. Charging by induction

We hope you find this article on Charging by Friction helpful. In case of any queries, you can reach back to us in the comments section, and we will try to solve them.

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