Electric power

Electric power is the rate of change of work done to transfer electrical energy from one source to any network. it’s SI unit of Watt, one joule per second.

Electric power is usually generated by electric generator whether it is AC generator or DC generator and we use this electrical energy in home and office or another commercial area. This electric power is supplied by the electric power grid. Electric power is usually sold by the Kilowatt-hour means 3.6 MJ. Kilowatt-hour comes from which power is multiplied by running time in hours.

Electrical Power has low Entropy form of energy and can be carried long distances and converted into other forms of energy such as motion, light or heat with high energy efficiency.

Definition:-

The electric power in watts produced by an electric current I consisting of a charge of Q coulombs every t seconds passing through an electric potential (voltage) difference of V is

where

Q is an electric charge in coulombs
t is the time in seconds
I is electric current in amperes
V is electric potential or voltage in volts

Explanation:-

As we know that an electrical energy is a very convenient form of energy which can be easily converted into another form of energy which required.
Electric power will be consumed or stored in an electric circuit and Electric circuit has two categories.

1. Passive devices or loads.
2. Active devices or power source

1. Passive devices or load:- When an electric potential is applied across the load and an electric charge flow through it due to the potential difference from positive polarity to negative polarity, work is done by the charge flowing through the load.

The potential difference compels the charges to flow and the potential energy converted into kinetic energy of the charge.
if the load consume power and convert it into any other form of energy then the load is called passive load. An example- electric motor, light bulb and electric heater etc.

Above animation show load behaviour.

2. Active devices or power sources:- If the charges are moved by an external force through the load from the lower potential to higher potential that device is called Active device or power sources.

Above animation showing power source