Electrons are emitted from a photosensitive surface when it is il… - Vidyadip

Question

Electrons are emitted from a photosensitive surface when it is illuminated by green light but electron emission does not take place by yellow light. Will the electrons be emitted when the surface is illuminated by (i) red light, and (ii) blue light?

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Answer

No.
Yes.

Reason: According to colour sequence VIBGYOR, the frequency of red light photons is less than threshold frequency of photo metal but frequency of blue light photons is more than threshold frequency of photo metal; so (i) electrons will not be emitted by red light and (ii) electrons will be emitted by blue light.

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