Question:
If a 10 W bulb emits electromagnetic waves uniformly in all directions, then the intensity of light at a distance 0.5 m from the source is nearly
If a 10 W bulb emits electromagnetic waves uniformly in all directions, then the intensity of light at a distance 0.5 m from the source is nearly
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For point sources, the intensity decreases with the square of the distance from the source.
Updated On: Jun 6, 2025
- 3.18 W/m²
- 0.31 W/m²
- 0.62 W/m²
- 5 W/m²
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The Correct Option is A
Solution and Explanation
The intensity of light is given by:
$$ I = \frac{P}{4 \pi r^2} $$
where $P$ is the power of the bulb, and $r$ is the distance from the source.
Substituting the given values, the intensity at a distance of 0.5 m is approximately 3.18 W/m².
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