Page 40 - Basic Electrical Engineering
P. 40
1.8.1 Work
When a force is applied to a body causing it to move, and if a displacement, d
is caused in the direction of the force, then
Work done = Force × Distance (1.10)
or, W = F × D
If force is in Newtons and d is in meters, then work done is expressed in
Newton−meter which is called Joules.
1.8.2 Power
Power is the rate at which work is done, i.e., rate of doing work. Thus,
The unit of power is Joules/second which is also called Watt. When the
amount of power is more, it is expressed in Kilowatt, i.e., kW.
3
1 kW = 1 × 10 W
We have earlier seen in eq. (1.3), that electrical potential, V is expressed as
or,
Electrical Power,
