What is electrical power

All of these are forms of energy transfers. Example electric components, which transfer electric energy to another form. Electric energy in particular, begins as electric potential energy -- what we lovingly refer to as voltage. When electrons flow through that potential energy, it turns into electric energy.

In most useful circuits, that electric energy transforms into some other form of energy. Electric power is measured by combining both how much electric energy is transferred, and how fast that transfer happens. Each component in a circuit either consumes or produces electric energy. A consumer transforms electric energy into another form. For example, when an LED lights up, electric energy is transformed into electromagnetic. In this case, the lightbulb consumes power.

Electric power is produced when energy is transferred to electric from some other form. A battery supplying power to a circuit is an example of a power producer. Energy is measured in terms of joules J. Since power is a measure of energy over a set amount of time, we can measure it in joules per second. The SI unit for joules per second is the watt abbreviated as W.

Laptop and desktop computers operate in the standard watt power range. Energy consumption of a house is usually in the kilowatt range. Large stadiums might operate at the megawatt scale. And gigawatts come into play for large-scale power stations and time machines. Electric power is the rate at which energy is transferred. Given the few basic electricity terms we know, how could we calculate power in a circuit? Put the two together and what do we get?! To calculate the power of any particular component in a circuit, multiply the voltage drop across it by the current running through it.

How do we calculate the power across the resistor? First we have to find the current running through it. Easy enough Climate Change. Climate Feedback.

Ocean Acidification. Rising Sea Level. Electric power. NJ: Prentice-Hall, , ch. Contact us About us Privacy policy Terms of use. The reactive power is the power that is dissipated in reactance of the circuit. The relation can be explained using the following equation;. The ratio between of the active or real power the power that is actually dissipated in the circuit to the apparent power the total power supplied to the circuit is known as Power Factor.

If the Power Factor is maximum. It is only possible if the total reactance of the circuit is zero. In such case the real power P is equal to the apparent power S i. According to the relation;. If the Power Factor is minimum. Related Posts:. As per law the energy we get is a conversion of another energy form, so my question is that in step up transformers the output voltage we get is more than the inputs voltage, so which energy converts into that increased voltage at out put terminal of step up transformer?

Your email address will not be published. Notify me of follow-up comments by email. The amount of power dissipated in a circuit can be easily determined. It is simply the product of the potential difference or voltage across the particular element, multiplied by the current flowing through it.

In other words. In some instances the actual resistance of the circuit element may be known. For example the mains voltage may be known to be volts and the element resistance may be known to be By performing some simple algebra it is possible to discover the very useful formulae:. Using these formulae it is simple to work out the power dissipated in the Power is one of the key units in many electronic circuits.

It can be used to indicate the level of heat dissipated in a unit or even an individual component, it can be used to define the power consumed, and it can also be used to define the amount of power generated by the system to pass on to the next item.