Write Einstein’s photoelectric equation using the quantum picture of
radiation.
Explain briefly the three characteristic features observed in photoelectric
effect which can be explained by Einstein’s equation and not by the wave
theory of light.

 

 

 
 
 
 
 

Answers (1)
S safeer

According to Einstein’s the discrete unit in radiation is called quanta of energy of radiation. Each particle have an energy h \vartheta.
From this, it is clear that light is made up of these type of discrete units or packets of energy or quantum energy. it is called photon and it carries energy. When a photon incident on metal the energy of a photon is utilised for two purposes. One is to overcome the attraction of the metallic surface and another part is for gaining kinetic energy.
so kinetic energy of electrons = Energy obtained from the photon - energy used to escape from the metallic surface.
That is
       Kinetic energy = h \vartheta -\phi
where \phi is work function which is constant for a given substance.
This above equation is Einstein’s photoelectric equation.
The features of photoelectric effect which cannot be explained by the wave theory of light are
i) Kinetic energy of emitted electrons are found to be independent of incident light
ii) The electrons are emitted only at a particular frequency called threshold frequency. Below that frequency. no photoemission takes place
iii) Number of photoelectrons emitted from the metal per second is directly proportional to the intensity of radiation. As intensity increases the number of energy quanta per unit area per second increases

Preparation Products

Knockout NEET July 2020

An exhaustive E-learning program for the complete preparation of NEET..

₹ 15999/- ₹ 6999/-
Buy Now
Rank Booster NEET 2020

This course will help student to be better prepared and study in the right direction for NEET..

₹ 9999/- ₹ 4999/-
Buy Now
Knockout JEE Main July 2020

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 12999/- ₹ 6999/-
Buy Now
Test Series NEET July 2020

Take chapter-wise, subject-wise and Complete syllabus mock tests and get in depth analysis of your test..

₹ 4999/- ₹ 2999/-
Buy Now
Knockout NEET May 2021

An exhaustive E-learning program for the complete preparation of NEET..

₹ 22999/- ₹ 11999/-
Buy Now
Exams
Articles
Questions