Calculate phank constant by using enstein photoelectric equation
Answers
Since wave theory could not explain the photoelectric effect, Einstein proposed a particle theory of light for the first time
He said that radiations are made up of specific and discrete packets of energy called as quanta of radiation energy. Each energy quantum has a value equal to hv, where h = Planck’s constant, and v = frequency of incident light
These specific packets of quanta of energy are known as photons
When a light of frequency(v) (having energyhv ) is incident on a metal surface of work function(Φo), 3 cases could be possible
Case-1-When (hv < Φo), i.e., energy of photon is less than the work function of metal , no photoelectric emission occurs
Case-2- When (hv = Φo), i.e., energy of photon is exactly same as the work function of metal, then electrons get enough energy to just escape the metal surface.
Case-3- When (hv > Φo),e., energy of photon is greater than the work function of metal. Then electron, apart from getting energy to escape the metal surface, the remaining energy is provided to the electron as kinetic energy. Mathematically, it can be expressed as:
hv = Φo + Kmax
Here, Kmax is the maximum kinetic energy of a photoelectron
The above equation is known as Einstein’s photoelectric equation