(a) (i) Define Electric Power and write its SI unit. [1/2 + 1/2] (ii) Two bulbs rated 100 W; 220 V and 60 W;…
(a) (i) Define Electric Power and write its SI unit. [1/2 + 1/2]
(ii) Two bulbs rated 100 W; 220 V and 60 W; 220 V are connected in parallel to an electric mains of 220 V. Find the current drawn by the bulbs from the mains. [2]
Solution
(a)(i) The rate at which electric energy is dissipated or consumed in an electric circuit.
S.I. unit—watt / V. A / joule per second
(ii)
Current drawn by first bulb
I1 = 100 W / 220 V = 100/220 ampere
Current drawn by second bulb
I2 = 60 W / 220 V = 60/220 ampere
Both the bulbs are in parallel
Total current, I = I1 + I2
= (100/220 + 60/220) ampere = 160/220 A = 0.73 A
(Accept any other method)