Question

Two electric bulbs, one of 220 V -40 W and other of 200 V - 100 W are connected in house wiring circuit.

• A. The resistance of 100 W bulb is more than that of 40 W bulb.
• B. The resistance of 40 W bulb is more than that of 100 W bulb.
• C. The resistances of bulbs are equal.
• D. Both the bulbs carry equal currents.

Answer 1

The correct option is B The resistance of 40 W bulb is more than that of 100 W bulb.

We know that $P=\frac{V^2}{R}$

In parallel combination voltage across elements is same hence $P\propto \frac{1}{R}$
Hence, the resistance of 40 W bulb is more than that of 100 W bulb.