AP EAMCET · PHYSICS · Electromagnetic Waves
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
- A \(3.18 \mathrm{~W} \mathrm{~m}^{-2}\)
- B \(0.31 \mathrm{~W} \mathrm{~m}^{-2}\)
- C \(0.62 \mathrm{~W} \mathrm{~m}^{-2}\)
- D \(5 \mathrm{~W} \mathrm{~m}^{-2}\)
Answer & Solution
Correct Answer
(A) \(3.18 \mathrm{~W} \mathrm{~m}^{-2}\)
Step-by-step Solution
Detailed explanation
\(I = \frac{P}{4\pi r^2}\) \(I = \frac{10}{4\pi (0.5)^2}\) \(I = 3.18 \mathrm{~W} \mathrm{~m}^{-2}\)
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