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Electric charges and their conservation

In this topic, we will learn about electric charges, properties of electric charges, their types and the conservation of charge and how it functions.

The electric charge is defined as the property of the matter that is due to its subatomic particles. It causes the material to experience a force when placed in a magnetic and electric field.

The electric charge is a scalar quantity. It has both magnitude and direction but is an exception to the general vector quantities. If it has been a vector quantity, the two charges meeting at one point will result in the vector sum of the total charges. But it is not the same as the sum of the combined charges due to two different charges connecting at one point to the algebraic sum of both. Hence, despite having magnitude and direction, electric charge is quantized as a scalar quantity only.

Its symbol is “Q.” The SI unit of electric charge is Coulomb, and other units include Faraday, Ampere-Hour, etc.

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Types of electric charge:

There are only two types of electric charge:

Positive charge and negative charge

The positive charge is denoted by (+) and is the charge on the protons in the atom. If a material has a positive charge, the number of protons is higher than the number of electrons.

The negative charge is denoted by (-) and is the charge of the electron in the atom. If a material has a negative charge, the number of electrons is higher than the number of protons.

When there is a balance between the number of protons and the number of electrons in the material, the total charge is neutral.

Basic Properties of Electric Charge

The electric charges are called point charges when the dimension of the electrically charged bodies is minimal. Let’s take a note of the basic properties of electric charge. 

  1. Additive property of electric charge: Electric charges are cumulative, and the type of electric charge they carry influences this property. It has a scalar value. It is possible to add the charges directly. Consider the following scenario: a system with only two charges, q1 and q2.
  2. Conservative Nature of Electric Charge: A particle’s electric charge is conservative. It signifies that the charge can’t be created or eliminated in any way. Conduction and induction are two mechanisms that can transfer charges from one system to another. 
  3. Quantization of Charge: This is one of the fundamental properties of electric charge. The charge is technically a quantised quantity. The integral multiples of the basic unit of charge (i.e. 1.6 × 10-19 C) can be used to indicate a system’s net charge. If the body’s net charge is q, the equation can be stated as:

q = ne

n can be 1, -1, 2, -3, 4, -5 and so on. 

Methods of charging:

There are three different ways to charge any material. These are:

  1. Charging through friction: In this process, the charge transfer occurs when two different objects are rubbed together. It is possible as one object gains electrons while the other object loses electrons. The object losing electrons becomes positively charged while the one achieving electrons gains some charge, i.e., negative charge. 
  1. Charging through conduction: In this process, the charge transfer takes place by bringing the uncharged material close to the charged material. The electron’s charge is passed as the charged material loses its charge carriers to the uncharged material when both are nearby. 
  2. Charging through induction: In this process, the charge transfer occurs when two different objects are distantly located. Hence, in this process, there is no close contact between the two things. 

How to measure electric charge?

Coulomb is the SI unit of electric charge that is the quantity of charge transferred in one second. Hence, electric charge is calculated as:

Q=I×t

Here,

Q is the electric charge

I is the electric current

t is the time

Coulomb’s Law

Coulomb’s Law defines the strength of the force between two charges that may be attracting or repelling each other. Hence, According to Coulomb’s law,  the electrostatic force between two different objects is dependent on the charge of the bodies. There are also few charged bodies in any substance known as neutrons. These bodies are, moreover, neutral and help in generating electrostatic force. 

The expression represents it:

F= kq1q2/ r2 

Here,

F is the electrostatic force

K is the Coulomb’s constant and is equal to 8.988 × 109 Nm2/C2

q1 and q2 are point electric charges

r is the distance between the two point charges.

Conservation of Charge

According to the rule of conservation of charge, the total electrical charge in an isolated system always remains constant. This means that there are an equal amount of positive and negative charges. Hence the total charge of the universe is conserved and remains constant.

The net charge of the total charge of a body depends on the number of electrons and protons. The electrons are negatively charged particles, and protons are positively charged particles. For a body to be neutral, the electrons and the protons are exactly the same in number. Therefore the conservation of charge is always maintained. 

Explanation of the Conservation of Charge

To understand the conservation of charge in a microstructure, one must understand the composition of different bodies.

  • The first is the fact of the neutral charge. To remain constant and for the energy to be conserved, there needs to be a balance in the whole system. In a body, the number of protons or the positive charge should be equal to the electron of the negative charge. Hence, these two charges balance each other.
  • When we talk of electrical charge transfer, electrons are the major participants. At a normal state of the ideal state, the entire charge of the system is evenly distributed. Regarding the concentration of negative charge in some bodies, the transfer of electrons occurs from the bodies with higher polarity to lower polarity. 

Conclusion :

In this article, we have mentioned different points about the conservation of charge and its related electrical charge application. Electric charges are special entities that create electrical fields. It is the production of these fields that help the numerous electric appliances that we currently use.

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