When a point light source, of power E emitting monochromatic light of wavelength λ is kept at a distance r from a photosensitive surface of work $$-function$$ ϕ and area s, then number of photons striking the surface per unit time is

Question

When a point light source, of power E emitting   monochromatic light of wavelength λ is kept at a distance r from a photosensitive surface of work $$-function$$ ϕ and area s, then number of photons striking the surface per unit time is

Infinity Learn · Accepted Answer

The number of photons released per unit $$timen=$$ power  energy of each photon $$=w(hc/$$λ$$)These$$ photons are spread out in all directions over an area $$4$$$$π$$$$r2$$. The share of an area s is $$s/4$$$$π$$$$r2$$ of total  number of photons. So, the number of photons striking area s of $$photo-sensitive$$ surface per unit timen′$$=W(hc/$$λ$$)$$×$$s4$$$$π$$$$r2=W$$λ$$s4$$$$π$$$$hcr2$$

When a point light source, of power E emitting monochromatic light of wavelength $λ$ is kept at a distance r from a photosensitive surface of work -function $ϕ$ and area s, then number of photons striking the surface per unit time is

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When a point light source, of power E emitting monochromatic light of wavelength λ is kept at a distance r from a photosensitive surface of work -function ϕ and area s, then number of photons striking the surface per unit time is

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

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When a point light source, of power E emitting monochromatic light of wavelength $λ$ is kept at a distance r from a photosensitive surface of work -function $ϕ$ and area s, then number of photons striking the surface per unit time is