Basic Properties of Electric Charge and its Important Points

Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. It is carried by subatomic particles like electron and proton. Electrons are negatively charged while protons are positively charged.

Basic Properties of Electric Charge

1.Additivity of charge

The total charge of the system is obtained by adding algebraically. This is because charges add up like real numbers or they are scalars like the mass of a body. 

2.Charge is conserved

A charge can neither be created nor be destroyed only it can be transferred from one body to another. It means that the total charge of an isolated body is always conserved.

3.Quantisation of charge 

It is experimentally established that all free charge is an integral multiple of a basic unit of charge denoted by e. Thus charge on a body is given by 
   Q = ne

Important Points 

• The basic unit of charge is the charges that an electron or proton carries.
• Electric charge is always an integral multiple of e is termed as quantisation of charge.
• The quantisation of charge was first suggested by English experimentalist Faraday.
• The Quantisation of charge was experimentally demonstrated by Mullikan in 1912.
• One coulomb is the charge flowing through a wire in 1 s if the current is 1 A (ampere).
• Value of e = 6.02192 x 10-¹⁹C
• If the sizes of the charged bodies are very small as compared to the distances between them then it is said to be point charges.
• SI unit of charge is the coulomb.
• A charge is denoted by C.
• Mass of a body is always positive while charge can be either positive or negative.
• The Charge has only magnitude but no direction.
• Proper signs have to be used while adding the charges in a system.
• There are two types of charges, namely positive and negative.