Question

Define power. Derive its SI unit . What is the energy consumed in joules by an electric bulb rated 10W used for 5 minutes .

Answer 1

Dear Student ,
Power is defined as the rate of doing work .Again it can also be considered as the rate of energy consumed per unit tme .
S.I unit of power is J /s or watt .

Now the power consumed is ,
P = W /t = 10 / 300 = 0.033 J/s .
Regards