Q123 / 180 · COMEDK 2024 (Memory Based) · Physics
An electric bulb is rated at 220 V and 100 W . Power consumed by bulb when operated at 110 V will be
- A50 W
- B75 W
- C100 W
- Correct answerD25 W
Solution
$\quad P_{\text {rated }}=\frac{V_{\text {rated }}^2}{R}$ or $R=\frac{(220)^2}{100}$
Now, power consumed
$=\frac{V^2}{R}=\frac{(110)^2 \times 100}{(220)^2}=25 \mathrm{~W}$
Now, power consumed
$=\frac{V^2}{R}=\frac{(110)^2 \times 100}{(220)^2}=25 \mathrm{~W}$
Hence, the correct answer is option: 'D'.