Question

Three equal resistors connected in series across a source of e.m.f. together dissipate 10 watt. If the same resistors are connected in parallel across the same e.m.f., then the power dissipated will be

• A. 10 W
• B. 30 W
• C. 10/3 W
• D. 90 W

Answer 1

Answer: (D)

90 W

Answer 2

In series consumed power $P_{s} = \frac{P}{n}$ while in parallel

consumed power P_p = Np

⇒ P_P = n². P_s

⇒ $P_{P} = (3)^{2} \times 10 = 90W$