Question

A bulb is marked 100 W and 240 V. The resistance of the bulb is

• A. 41.66 Ω
• B. 250 Ω
• C. 24 Ω
• D. 576 Ω

Answer 1

The Correct Option is D

We are given that the bulb is marked with a power of 100 W and a voltage of 240 V. The resistance of the bulb can be found using the formula: \[ P = \frac{V^2}{R} \] Where:
\( P \) is the power (100 W),
\( V \) is the voltage (240 V),
\( R \) is the resistance.
Rearranging the formula to solve for \( R \): \[ R = \frac{V^2}{P} \] Substitute the values: \[ R = \frac{240^2}{100} = \frac{57600}{100} = 576 \, \Omega \] Thus, the resistance of the bulb is 576 ohms.

The correct option is (D): \(576\ Ω\)