Sr. No.Electric EnergyElectric power(i)Electrical energy consumed by anIt is the rate of whichelectrical appliance is given byelectrical energy isthe product of its power ratingconsumed.and time for which it is used.(ii)It is measured in kilowatt hour (kWh).It is measured in watt (W) orkilowatt (kW).
(b) We know, power (P) =V2R
i.e. At same voltage, power (P) is inversely proportional to resistance (R).
∴ 40 W lamp has higher resistance.
(c) The commercial unit of electrical energy is kWh.
1 kWh=1000 W×1 h =1000 W×3600 s
=36×105 Ws
=3.6×106 J.