Write two points of dillerence between electric energy and electric power Out of 60W and 40W lamps which one has higher elecrieal resistance when in use. What is the commerical unit of electric energy? Convert it into joules.

Write two points of dillerence between electric energy and electric po

1.	Write two points of dillerence between electric energy and electric power Out of 60W and 40W lamps which one has higher elecrieal resistance when in use. What is the commerical unit of electric energy? Convert it into joules.
Answer» SOLUTION :Electric energy The work done or energy supplied by the source in maintaining the flow of electriç current is called electrical energy. It appears in the from of heat given by `H = VIt = (v^(2)t)/(R)=1^(2)RT` It is cqual to be product of power and time E = P x t It SI unit is JOULE (J) 1J= 1Wx 1S Electric energy The time rate at which electronic energy is consumed or dissptied by an electrical divice is called electric power and is given by `P = VI = (v^(2))/(R) = I^(2)R` It is equal to the rate of doing work by an energy source `P = (W)/(t)` Its SI unit is watt(W) `1W = 1 JS^(-1)` (b) For the same applied voltage `P & (1)/(R)` i,e less the same power of clectrical device higher it is electrical resistance. ( c ) Kilowatt hour - commercial unit of electrical energy. 1 kwh = 1000 wh `= 1000 j//Sxx3600` see `3600000 J - 3.6 xx 10^(6)J`