What is electric energy and electric power derive the expression and define their unit?
Answers
The rate of work done to bring a test charge from infinity to a point in an electric field is known as electric power. Its S. I. unit is Watt(W)
ElectriCal energy is the capacity of any engine or device to do work.
The quantity of Energy is the unit that how much work we can do by this energy. Because the measuring unit of energy and worj is same.
If a device or machine has total energy of E , and we use some energy e to do a work , we will now have total of E-e rest quantity of Energy.
Similarly If we do positive work on the machine , we can increase the total energy of that machine.
The term Power is the rate of doing work or consuming energy by that device or machine.
To differentiate between Energy and Power , we can take an example.....
Let us take a machine JCB and a crane that can lift very heavy weights.
If we give same amount of energy ( fuel) to both machines...
JCB can only lift lighter weights than Crane . The crane will lift higher weights and Consume fuel faster than JCB.
Though , they have same energy , but their engines are different to consume fuel.
The engine of JCB will consume fuel slowly and can lift only lighter weights than crane.
The engine of crane will lift higher weights, so it will require much fuel to consume as it has more power