Custom Search

## ELECTRIC POWER

The rate at which electrical work is done by an electrical appliance is called electric power, i.e.

Power    =

P    =

but,    W    =    VIt

So       P    =

So       P    =    VI watt    (1)

Where,    V   =    potential difference (in volt)

I    =    current (in ampere)

Therefore,    P =   potential difference (in volt)   X   current (in ampere)

Also we know that according to Ohm’s law V   =   I R

Putting the value of I in equation (1), we get

P    =    IR   X   I
or       P    =    I2R

The S.I.unit of power is watt. It is denoted by the letter W.

1Watt

The power is said to be of 1 watt if 1 joule of work is done in 1 second. Thus,

1 watt    =

The S.I. unit of power represents a small amount of power and therefore it is inconvenient to use it where a large amount of power is involved. So, for commercial purposes a bigger unit of electric power called kilowatt is used.

1 kilowatt    =    1000 watt
or       1 KW          =    1000 W

1. What is electric power?

2. What is definition of 1 watt?

3. What is definition of kilowatt?

Developers of Fun Science
 Rajan Gupta M.Sc, B.Ed. & LL.B. Teacher, Author & Innovator Rahul Jindal B.Tech Entrepreneur & Innovator