Question

Two lamps one rated 100w at 220v and the other 200w at 220v are connected (i) in series (ii) in parallel to electric main supply. Find the current drawn in each case.

Answer 1

Explanation:

P= V×i

=> i = P/ V

(1) in series combination,

P = P1P2/(P1+P2)

= 100×200 / 300 = 150 watt

=> i = 150/220 = 15/22 amp.

= 0.68 amp

(2) in parallel combination,

P = P1+P2

= 300 watt

=> i = 300 / 220

= 15/11 amp = 1.36 Amp.

hope this helps you