, Topic 14 :
Dual Nature of Radiation An
Matter
Shri Swami Vivekanand Shikshan Sanstha, Kolhapur
,14.1 Introduction :
Light is electromagnetic radiation.
Electromagnetic radiation consists of mutually perpendicular oscillating electric and ma
fields
The idea of ‘quantization of energy’ was first proposed by planks to explain the black
spectrum, Planks proposed a model that says
(i) energy is emitted in packets
(ii) at highest frequencies, the energy of a packet is large
Shri Swami Vivekanand Shikshan Sanstha, Kolhapur
, * PHOTO ELECTRIC EFFECT:
The phenomenon of emission of electrons by metal surfaces, when radiations of suita
frequency is incident on it is called photoelectric effect and Emitted electrons are cal
photo electrons.
* THRESHOLD FREQUENCY
It is the minimum frequency of incident radiation for which the photoelectrons are
emitted from the surface of a metal. This minimum frequency is called threshold
frequency of that metal.
*PHOTO ELECTRIC WORK FUNCTION
The minimum energy required to release the electron from metal surface is called photo
electric work function of that metal. It is denoted by Φ0 . Its S.I unit is Joule.
Dual Nature of Radiation An
Matter
Shri Swami Vivekanand Shikshan Sanstha, Kolhapur
,14.1 Introduction :
Light is electromagnetic radiation.
Electromagnetic radiation consists of mutually perpendicular oscillating electric and ma
fields
The idea of ‘quantization of energy’ was first proposed by planks to explain the black
spectrum, Planks proposed a model that says
(i) energy is emitted in packets
(ii) at highest frequencies, the energy of a packet is large
Shri Swami Vivekanand Shikshan Sanstha, Kolhapur
, * PHOTO ELECTRIC EFFECT:
The phenomenon of emission of electrons by metal surfaces, when radiations of suita
frequency is incident on it is called photoelectric effect and Emitted electrons are cal
photo electrons.
* THRESHOLD FREQUENCY
It is the minimum frequency of incident radiation for which the photoelectrons are
emitted from the surface of a metal. This minimum frequency is called threshold
frequency of that metal.
*PHOTO ELECTRIC WORK FUNCTION
The minimum energy required to release the electron from metal surface is called photo
electric work function of that metal. It is denoted by Φ0 . Its S.I unit is Joule.
