JEE Mains · Physics · STD 12 - 8. Electromagnetic waves
A point light source emits E.M. waves in free space. A detector, placed at a distance of \(L\) m, measures the intensity as \(I_o\). The detector is now shifted to another location on the same spherical surface ensuring the angle between original location and new location as \(45°\). The measured intensity at new location will be _______.
- A \(\dfrac{I_o}{4}\)
- B \(I_o\)
- C \(\dfrac{I_o}{\sqrt{2}}\)
- D \(\dfrac{I_o}{2}\)
Answer & Solution
Correct Answer
(B) \(I_o\)
Step-by-step Solution
Detailed explanation
For a point light source, the intensity of electromagnetic waves at a distance \(r\) is given by \(I = \dfrac{P}{4\pi r^2}\), where \(P\) is the power of the source. Since the detector is moved to a new location on the same spherical surface, the distance from the source remains…
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