# How do you convert electrical energy into heat energy?

###### May 05, 2013 11:27AM

Whenever electrical current encounters resistance, heat is generated.

Many home heating appliances (e.g. toasters, water heaters) work on this principle as well as tools (e.g. soldering iron, hair dryer) and even industrial furnaces. In each case, the resistance doing the heating has its specific performance characteristics that is has to meet, but the underlying scientific principle is the same.

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The simplest electronic component is probably the resistor.

A resistor has no purpose other than to "resist" the flow of electricity. It performs no function other than turning electrical energy into heat energy. (Often the purpose is not to generate heat, but to control voltage or current and the generation of heat is secondary.)

If a current I flows through a resistor R, then the rate of power, P, is

P=I2R.

Similarly, if a voltage drop of V occurs across a resistor, the Power is,

P=V2/R.

These equations are the same as saying that power associated with a resistor is, P=VI.

The power is the rate at which heat is generated and therefore the rate at which electrical energy is converted to heat energy.