A 5 watt source emits monochromatic light of wavelength 5000 Å. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0 m, the number of photoelectrons liberated will be reduced by a factor of

Question

Dr. Abubacker · Accepted Answer

[Solution from source] The number of photoelectrons is proportional to intensity, which falls as 1/r². Doubling the distance from 0.5 m to 1.0 m reduces it by 2² = 4. A factor of 2 assumes intensity ∝ 1/r. Answer (4).

Q. A 5 watt source emits monochromatic light of wavelength 5000 Å. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0 m, the number of photoelectrons liberated will be reduced by a factor of

Explanation

Reviewed by Dr. Abubacker

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