Friday, June 24, 2011
2:21 AM | Posted by
Anonymous |
Electric Power and Electric Energy are very important Expression you need to know.
Power
The basic unit (measurement) of power is the watt (W), named after James Watt (1736–1819), who also invented the steam engine. Voltage by itself(only)does not do any actual work. Current by itself does not do any real work.
However, voltage and current together can produce real work. The product of voltage times current is power.
P = V * I .........equation (1)
Power is used to produce real work.
For example, electrical power can be used to create heat, spin motors, light lamps, and so on. The fact that power is part voltage and part current means that power equals zero if either voltage or current are zero.that is clear from above equation. Voltage might appear at your wall outlet in your home and a toaster might be plugged into the outlet, but until someone turns on the toaster, no current flows, and, hence, no power occurs until the switch is turned on and current is flowing through the wires.
Do you remember the example of water?? ok, I will repeat it again.
if you consider the Electric circuit like the water Pump system then the voltage corresponds to the pressure that pushes water through a pipe. The pressure is present even though no water is flowing.the Current corresponds to the water flow.this water flow can't occured without the pressure.the final amount of water depend on both.that's final amount corresponds to Power
Energy
Electrical energy is the product of electrical power and time. The amount of
time a load is on (current is flowing) times the amount of power used by the load (watts) is energy. The measurement for electrical energy is watt-hours (Wh). The more common units of energy in electric power systems are kilowatt-hours (kWh, meaning 1,000 watt-hours)
E = P * t .........equation (2)
for residential applications and megawatt-hours (MWh, meaning 1,000,000 watt-hours)
for large industrial applications or the power companies themselves. Do you feel confused confused about this lesson? Leave your question now in a comment.
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