Duduli

Einstein explained photoelectric effect on the basis of planck's theory. It is the matter of common observation that electrons are emitted only when light is incident on the metal. Thus, the metal surface behaves like a potential barrier. So some energy require to cross the barrier. The minimum amount of energy required to come out from the surface of metals is called work function. Let Wo be the work function. An incident photon supplies whole of its energy hμ to the electron & the electron consumes some energy Wo against work function & comes out with the remaining energy as kinetic energy. 1/2 MV²max = hμ - hμ' This is the einsteins equation of photoelectric effect.

Photoelectric effect is the phenomenon in which electrons are knocked off a metal surface when light is incident on it. The metal is said to be a photosensitive material and the liberated electrons are called photoelectrons.

Answer:- When large amount of external energy in the form of heat is supplied to the free electrons of the metal electrons are ejected from metal surface,that phenomenon is called Thermonic emission.

Answer:- To stop the flow of electron(means photocurrent) in Photoelectric effect we have to increase negative potential at the anode,that negative potential repel the incoming electrons. At which negative potential of anode electrons flow will completely stop that negative potential is called stopping potential.

Reason:-  Intensity of light increase means no. of photon increase, if no. of photon increase then they are  eject more electron from the metal surface that implies photocurrent increases because current increases with increase in no. of electron motion per unit time.(I=Q/t)  It is the answer to the question why photocurrent increases with increase in intensity of light.

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