# Electric power

## 03 Electricity

#### ELECTRIC POWER

• Electric power is the electrical work done per unit time. In other words, it is the rate at which work is done in an electric circuit.
• Electric power is represented as :

#### ELECTRIC POWER

• Electric power is the electrical work done per unit time. In other words, it is the rate at which work is done in an electric circuit.
• Electric power is represented as :

#### UNIT OF POWER

The SI unit of electric power is Watt which is denoted by the letter W.
The power of 1 watt is a rate of working of 1 joule per second. That is,

#### FORMULA FOR CALCULATING ELECTRIC POWER

Also, P is related to Q (electric charge) as:

where, Q is the charge (in Coulombs)

#### COMMERCIAL UNIT OF ELECTRICAL ENERGY IS KILOWATT-HOUR

Relation between kilowatt-hour and joule: 1 kilowatt-hour = 1000 watts for 1 hour