Biripali

  Electric potential :-         C url of electrical field is zero therefore, electric field is conservative field. Scalar potential is defined only for conservative field.        In the following we first show that curl of electric field is zero . We know field of a point charge at the origin.      If we take the integral along a closed path Then, . Apply Stoke theorm   Here,  This result can be generalised for any charge distribution using the principal of superposition. The general result is 

Coulomb's Law : The electrostatic force of interaction between two static point electric charge is directly proportional to the product of the charge, inversely proportional to the square of the distance between them and acts along the straight line joining the two charges. If two points charge q1 and q2 separately by a distance r. Let F be the electrostatic force between these two charge. According to Coulombs law.

Electric charge: Charge is the property associated with matter due to which it produces and experience electrical and magnetic effect.The excess or deficiency electrons in a body gives the concept of charge. Types of charge: 1. positive charge: It is deficiency of electrons as compared to protons. 2. Negative charge: It is excess of electrons as compared to proton. S.I. Unit of charge is Coulomb Dimensions: [A T] 1C = 3 x 10^9 stat coulomb,  1 absolute coulomb= 10C, 1 faraday = 96500C Specific property of charge: - Charge is a scalar quantity . - Charge is transferable. - charge is always associated with mass. - Charge is quantised. Q=ne - Charge is conserved. - Charge is invariant.