Electric Power

How is electric current converted into useful power? In this section we discuss this aspect of the electric circuits.

In a simple electric circuit, the electric current is made to flow through a resistor. A heater is a good example. When electric current flows through a heating coil, the coil gets hot and we put it to good use.

The power consumed by the heating coil (or any other resistance) can be calculated by using either one of the two formulas shown in the illustraion.

• The first formula uses the value of current and the value of resistance.
• The second formula uses the value of voltage and the value of current.

The unit for electric power is “watts.”