Summary
1) Electric potential is the condition that determines direction of flow of charge. Electrical potential at a point in an electric field is defined as the amount of work done in bringing a unit positive charge from infinity to that point.
2) Electrical potential is a scalar quantity.
3) The potential difference between two points in an electric field is the amount of work done in moving a unit positive charge from one point to the other.
4) The rate of flow of charges constitutes current.
5) Ohm’s law states that the current flowing through a metallic conductor is directly proportional to the potential difference across its ends, provided temperature and other physical conditions of the conductor remains the same.
6) The opposition or obstruction offered by a conductor to the passage of drifting electrons is called electric resistance.
7) Ohm is the unit of resistance.
8) When the resistances are combined in series the equivalent resistance is the sum of the individual resistance.
9) When the resistances are connected in parallel the reciprocal of the equivalent resistance is equal to the sum of the reciprocals of the individual resistances.
10) The amount of heat generated in a conductor of resistance ‘R’, when current ‘I’ flows through it in a given time ‘t’, is given by I2 Rt.
11) Electric power is defined as the rate at which electric energy is dissipated or consumed in an electric circuit.
12) Electric power is said to be one watt if a potential difference of one volt causes a current of one ampere to flow through a conductor.
13) Kilowatt-hour or kWh is the commercial unit of electrical energy.
14) 1 kWh is defined as the amount of electrical energy consumed in 1 hour when the rate of consumption is 1000Joules/second
1kWh = 3.6 x 106 Joules.
