Two lamps, one rated 40 W at 220 V and the other 60 W and 220 V, are connected in parallel to the electric supply at 220 V.

(a) Draw a circuit diagram to show the connections.


(b) Calculate the total energy consumed by the two lamps together when they operate for one hour.

(a)

(b) As the connection is in parallel.


So voltage across both the bulbs is same and is equal to 220V.


Current through AB i.e 40W lamp = I1 = P1/V = 40/220 A


Current through CD i.e. 60W lamp = I2 = P2/V = 60/220 A


Total current drawn from the electric supply = 40/220 + 60/220 = 0.45 A


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