# Power in Physics and Electricity

Learn about Power in Physics and Electricity with Definition, Unit, Formula, Calculation and Examples.

Here we Learn about Power in Physics and Electricity with Definition, Unit, Formula, Calculation and Examples.

## Definition of Power in Physics

Some of the definition of Power in Terms of Physics and Electricity are:

**Electrical Power**: The product of voltage and current.- Electric power is defined as the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the
**watt**. - Electric energy produced per unit time.

Current flowing through a poor conductor produces heat by an effect similar to mechanical friction. That heat represents energy that comes from the charge traveling across the voltage difference.

Remember that separated charges have the potential to do work and provide energy.

The work involved in heating a resistor is not very useful, unless we are making a hotplate; rather it is a byproduct of restricting the current flow.

Power is measured in **unit** of watts (**W**), named after James Watt, the Englishman who invented the steam engine, a device for producing lots of useful power.

## Formula to Calculate Power in Electricity

The power that is released into the resistor as heat can be calculated as **P=VI** , where **I** is the current flowing through the resistor and **V** is the voltage across it.

Ohm’s law relates these two quantities, so we can also calculate the power as the power produced in a resistor raises its temperature and can change its value or destroy it.

Most resistors are air-cooled and they are made with different power handling capacity. The most common values are 1/8, 1/4, 1, and 2 watt resistors, and the bigger the wattage rating, the bigger the resistor physically.

Some high power applications use special water cooled resistors.

## Formula to Calculate Power in Physics

Power is the rate at which work is done.

**P = W / T; **where **P** = Power, **W** = work Done, **T** = Time Taken to do the Work.

## Related Posts:

**Electronics Definition****Electronics Dictionary****Rules of Electrical Circuit in Parallel and Series****How is Electricity Generated, Transmitted and Distributed?****Electronics and Electricity Basics****What is an Electronic Circuit?****Types of Electric Current – AC (Alternate Current) | DC (Direct Current)****Electronic Circuits for Beginners****How Solar Power Works****Potential Difference****Active and Passive Electronic Components****How Electronic / Electrical Circuit Works**

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