Question

Two monochromatic radiations of frequencies v1 and v2 (v1 > v2) and having the same intensity are, in turn, incident on a photosensitive surface to cause photoelectric emission. explain, giving reason, in which case (i) more number of electrons will be emitted and (ii) maximum kinetic energy of the emitted photoelectrons will be more.

Answer 1

i) number of electrons emitted is directly proportional to intensity.Thus same no. of e- will be emitted from both.

ii) k.E = hv
as v1 > v2
:. K.E. of 1 radiation is more.

Answer 2

I) For both of the given frequencies , the number of electrons emitted will be equal because they have equal intensity.

II) Kinetic energy of the electrons emitted during photoelectric effect is directly proportional to the frequency of the incident light .

Given v1 > v2 , so for frequency v1 the kinetic energy of the electrons will be more than v2.