Electric potential, potential difference, capacitance

Electric Potential Difference

Electric potential difference

Electric potential difference

Electron-volt (e. V) The amount of work done in moving an elementary charge through a potential difference of 1 V. 1 e. V = 1. 6 x 10 -19 J

Electric potential due to point charges The electric potential at a point is equal to the electric potential energy (measured in joules) of any charged particle at that location divided by the charge (measured in coulombs) of the particle.

Electric potential due to point charges

Electric potential at very large distance from q

Ground point and absolute potential Ground point is a point where the electric potential is defined as zero. Absolute potential is the value of voltage at other points relative to the reference point of zero potential.

Equipotential lines are lines which trace lines of equal electric potential or voltage. Equipotential lines are always perpendicular to the electric field. Movement along an equipotential surface requires no work because such movement is always perpendicular to the electric field.

Equipotential lines

Equipotential lines

Electric Potential at an Arbitrary Point due to Two Point Charges To find the electric potential due to two point charges, simply take the sum of the potentials, at that point, due to each charge. r 1 P +Q 1 r 2 Q 2 Note – these are not vector quantities !

Electric potential at a point has no real significance , mainly because you have nothing to compare it to. Typically, the potential of a point is discussed relative to another point of known potential. Therefore, we usually look at the potential difference or (change of voltage, V) voltage between two points.

Electric potential difference between two points due to a point charge q