Question

Give a brief description of the basic elementary process involved in the photoelectric emission in einstein’s picture class 12

Answer 1

photoelectric effect :- this is based on planks quantum theory .

photon :- photon is the smallest package of energy . according to plank's quantum theory, energy emitted in metal or element like package of energy. which is known as photon .
E = hv
here h is plank 's constant , v is the frequency .
here hv is smallest energy emitted from element . e.g energy of each of photon is hv .

now we go to photoelectric emission :-
this is given by Albert Einstein .according to this theory if suitable frquency of ray of light striking the metal surface , some amount of energy used to ejection of electron from metal and rest energy give motion to the electron.

e.g E = hv - @
= hv - hv°

hv is initial energy of photon which strike to the metal surface . @ is wave function .e.g energy required to remove electron from metal surface .

equation another form ----------------

E = hc/lemda - hc/lemda°

lemda° is the cut off wavelength . it is always then wavelength of initial photon' s wavelength for emission of electron.

Answer 2

Answer:

• On interaction of radiation with matter, it behaves as if it is made up of particles called photons.
• Each photon has energy E = hγ, momentum p = mv and speed = c, the speed of light.
• All photons of light of particular frequency having wavelength λ have same energy and momentum whatever may be the intensity of light. By increasing the intensity of light of given wavelength there is only increase in number of photons per second crossing the area. i.e., photon energy is independent of intensity.
• Photons are electrically neutral and are not deflected by electric and magnetic field.
• In  particle-photon collision  total energy and momentum are conserved but the number of photons emitted may not be.