(a) Write two points of difference between electric energy and electric power (b) Out of 60w and 40w lamps which one has higher electrical resistance when in use?

a) Difference Between Electric power and electrical energy.

  1. The work is done or energy supplied by the source in maintaining the flow of electric current is called electrical energy whereas he time rate at which electric energy is consumed or dissipated by an electrical device is called electric power
  2. It is equal to the product of power and time i.e. E = P × t whereas electric power is equal to the rate of doing work by an energy source i.e. P = W/T

b) Less the power of the electrical device, higher is its electrical resistance.

c) Kilowatt-hour – Commercial unit of electrical energy 1 kWh = 1000 Wh = 1000 J/S x 3600 sec = 3600000 J = 3.6 x106

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