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The electrons so emitted were called photoelectrons. J. J. Thomson showed that the photoelectrons were not different from the ordinary electrons.
Laws of photoelectric emission. The various experimental observation led to the various conclusions, which became known as the laws of photoelectric emission, as explained below:
1. The emission of photoelectrons takes place only when the frequency of the incident radiation is above a certain critical value, characteristic of that metal. The critical value of frequency is known as the threshold frequency for the metal of the emitting electrode.
2. The emission of photoelectrons starts as soon as light falls on metal surface.
It has been found that the time lag between the incidence of photon and the emission of electron is less than 10-8 s.
3. The maximum kinetic energy with which an electron is emitted from a metal surface is independent of the intensity of the light and depends only upon its frequency.
4. The number of photoelectrons emitted i.e. the photoelectric current is independent of the frequency of the incident light and depends only upon its intensity.
Einstein's Photoelectric Equation
To explain photoelectric effect, Einstein postulated that the energy carried by a photon of radiation of frequency v is hv. According to him, the emission of a photoelectron was the result of the interaction of a single photon with an electron, in which the photon is completely absorbed by the electron. We know that to remove an electron from a metal, a certain minimum amount of energy w, called work function of the metal, is required. Thus, when a photon of energy hv is absorbed by an electron, an amount of energy at least equal to w (provided hv> w) is used up in liberating the electron free and the differeace hv-w becomes available to the electron as its maximum kinetic energy."
૭૫. મુનિ યશોવિજયજી, પૂર્વ ઉદ્ધૃત ગ્રન્થ, પૃષ્ઠ ૧૦૦
૭૬. એજન, પૃષ્ઠ ૧૦૧, ૧૦૨ ઉપર આ ઉદાહરણ વિસ્તારથી દર્શાવેલ છે. ૭૭. એજન, પૃષ્ઠ ૧૦૩
૭૮. એજન, પૃષ્ઠ ૧૦૩, ૧૦૪
૭૯. એજન, પૃષ્ઠ ૧૧૬, ૧૧૭
૮૦. એજન, પૃષ્ઠ ૧૦૪, ૧૦૫
૮૧. તેરાપંથ યુવક પરિષદ જયપુર દ્વારા પ્રકાશિત ‘જય શાસન જય
Jain Educationa International
272
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| SR No. | 005303 |
| Book Title | Shu Vidyut Sachit Teukay Che |
| Original Sutra Author | N/A |
| Author | Mahendramuni |
| Publisher | Anekant Bharati Prakashan |
| Publication Year | 2005 |
| Total Pages | 312 |
| Language | Gujarati |
| Classification | Book_Gujarati |
| File Size | 13 MB |