Question

Write two points of difference between electric energy and electric power.

Answer 1

Answer:

Explanation:

Electrical Energy

(i) The work done or energy supplied by the source in maintaining the flow of electrical current is called electrical energy. It appears in the form of heat by                  

                      H = VIt = V²t/R = I²Rt

(ii) It is equal to the product of power and time taken :

                      E = P × t

(iii) Its SI unit is Joule (J)

                      1 J = 1 w × 1 sec

Electric Power

(i) The time rate on which the electrical energy is consumed or dissipated by an electrical device is called electric power and given by :

                      P = VI = V²/R = I²R

(ii) It is equal to the rate of doing work by an energy source and it is given by :

                       P = W/t

(iii) Its SI unit is Watt (W)

                       1 W = 1 J s⁻¹