Question
Define the term electric potential due to a point charge. Calculate the electric potential at the centre of a square of side having charge 100 μC, – 50 μC, 20 μC and – 60 μC at the four corners of the square.
Solution
Electric potential at a point is defined as the amount of work required to carry a unit positive charge with zero acceleration from infinity to that particular point under consideration in electric field, against the electrostatic forces.
Side of the square,a =
Charge, qA = 100 μC
Side of the square,a =
Charge, qA = 100 μC
Charge, qB = – 50 μC
Charge, qC = 20 μC
Charge, qD = – 60 μC

Diagonal of the square, AC =
Distance of any charge from centre O = AC/2 = 1m.
Potential at the centre of the square,
Charge, qC = 20 μC
Charge, qD = – 60 μC

Diagonal of the square, AC =
Distance of any charge from centre O = AC/2 = 1m.
Potential at the centre of the square,