Question

Two electric bulb one of 200 volt and 40 watt and the other of 200 volt and 100 watt are connected in a house wiring circuit.

• A. They have equal currents through them.
• B. The resistance of the filaments of both the bulb is same.
• C. The resistance of the filament of 40 W bulb is more than of 100 watt bulb.
• D. The resistance of 100 W bulb is more than 40 watt bulb.

Answer 1

Answer: (C)

The resistance of the filament of 40 W bulb is more than of 100 watt bulb.

Here, two electric bulb one of 200 volt and 40 watt and the other of 200 volt and 100 watt are connected in a house wiring circuit, the power of both the bulbs are
$R_1=\frac{V^2}{P_1}$ and$R_2=\frac{V^2}{P_2}$

$\therefore R_1=\frac{{200}^2}{40}=1000\Omega$ and

$R_2=\frac{{200}^2}{100}=400\Omega$

Hence, $R_1>R_2$