Two bulbs consume the same power when operated at 200 V and 300 V respectively. When these bulbs are connected in series across a DC source of 400 V , then the ratio of power consumed across them is

Step-by-step solution

R = V 2 P o r R ∝ V 2 ∴ R 1 R 2 = 200 2 300 2 = 4 9 . When bulbs are connected in series, the current I is same through each. As P = I 2 R o r P ∝ R ( a s I is same in series), so P 1 P 2 = R 1 R 2 = 4 9 .