Question

All properties of the charge

Answer 1

Basic Properties of Electric Charge

As charges are of two types, positive and negative, there are other certain basic properties they follow. If the size of charged bodies is so small, we consider them as point charges. The basic properties of electric charges are as follows:

• Charges are additive in nature

• Charge is a conserved quantity

• Quantization of charge
  

Charges are additive in nature

Charges are additive in nature means they’re like scalars and can be added directly. For An Example consider a system which consists of two charges namely q₁ and q₂. Now we wish to find the total charge of the system. The total charge of the system will be the algebraic sum of q₁ and q₂ i.e.q₁ + q₂. The same thing holds for a number of charges in a system. Let's say a system contains q₁,q₂,q₃,q₄……….q_n, then the net charge of the entire system will be

= q₁ + q₂ + q₃ + q₄ + ………………………..+ q_n

The charge is a scalar quantity as it has only magnitude and no direction. The charge is just as other fundamental properties of the system like mass. The only difference between mass and charge is that charge is both positive and negative, while mass is always positive.

Charge is a conserved quantity

The charge is a conserved quantity which means charge can neither be created nor be destroyed but can be transferred from one body to another by certain methods like conduction and induction. As charging involves rubbing two bodies, it is actually a transfer of electrons from one body to another. We can’t create a charge in a body but eventually can transfer them to another body with some convenient methods.

In a system when charges are distributed accordingly, by the principle of conservation the net charge of the system remains constant. As an example if 5 C is the total charge of the system, then it can be redistributed as 1C, 2C and 2C or in any other possible permutation, but by conservation principle the net charge of system will always be 5 C. Although the charge carriers may be destroyed in a system but the net charge will remain conserved.

Quantization of Charge

Quantization of charge means that charge is a quantized quantity and is expressed as integral multiples of the basic unit of charge (e – charge on one electron). Suppose charge on a body is q, then it can be written as

q = ne

where n is an integer and not fraction or irrational number, like ‘n’ can be any positive or negative integer like 1, 2, 3, -5 etc.

The basic unit of charge is the charge acquired by an electron or proton. By convention we take charge on the electron as negative and denote it as “-e” and charge on a proton is simply “e”. The quantization of charge principle was first proposed by English experimentalist Faraday when he put forward his experimental laws of electrolysis. The principle was finally demonstrated and proved by Millikan in 1912.

1 A Coulomb of charge contains around 6 × 10¹⁸ electrons. Particles don’t have a high magnitude of charge and we use micro coulombs or milli coulombs in order to express charge of a particle.

1 μC = 10^-6 C

1 mC = 10^-3 C

The principle of quantization can be used to calculate the total amount of charge present in a body and also to calculate a number of electrons or protons in a body.

Suppose a system has n₁ number of electrons and n₂ number of protons, then total amount of charge will be n₂e – n₁e.