Electric Charges and Fields

Electric Charge :

Charge is the property associated with matter due to which it produce and experiences electric and magnetic field.

Conductor and Insulator :

Those substances which readily allow the passage of electricity through them are called conductors, e.g. metals, the earth 

 And, 

      Those substances which offer high resistance to the passage of electricity are called insulators, e.g. plastic rod and nylon.

• Transference of electrons is the cause of frictional electricity.

• Additivity of Charges Charges are scalars and they add up like real numbers. It means if a system consists of n charges q₁, q₂, q₃ , … ,q_n, then total charge of the system will be q₁ +q₂ + … +q_n.

#. Conservation of Charge : The total charge of an isolated system is always conserved, i.e. initial and final charge of the system will be same.

#. Quantisation of Charge : Charge exists in discrete amount rather than continuous value and hence, quantised.

Mathematically, charge on an object, q=±ne
where, n is an integer and e is electronic charge. When any physical quantity exists in discrete packets rather than in continuous amount, the quantity is said to be quantised. Hence, charge is quantised.

#. Units of Charge is coulomb (C).