Question

Two 220-volt, 100-watt bulbs are connected first in series and then in parallel. Each time the combination is connected to a 220-volt a.c. supply line. The power drawn by the combination in each case respectively will be:

• A. 50 watt,100 watt
• B. 100 watt,50 watt
• C. 200 watt,150 watt
• D. 50 watt,200 watt

Answer 1

Answer: (D)

50 watt,200 watt

Answer 2

If rated voltage = supply voltage then use
$\frac{1}{P}=\frac{1}{P_1}+\frac{1}{P_2}$ (series connection) & P = P1 + P2 (parallel connection)