Answer: 3.5 kWh
Explanation:
Given that the
Power P = 500 W
To convert watt to kilowatt, divide it by 1000
Power P = 500/1000 = 0.5 kw
Time t = 7 hours
Power is the rate at which work is done. That is,
P = WD/t
Cross multiply
WD = Pt
Where workdone WD is the energy E consumed in kWh .
Substitute P and t in the formula above.
E = 0.5 × 7
E = 3.5 kWh
Therefore, 3.5 kWh (kilowatt hours) of electricity is consumed by a 500 w light bulb that burns.
