Einstein photoelectric effect class 12

The photoelectric effect is a phenomenon where electrons are emitted from the metal surface when light of sufficient frequency is incident upon it. The concept of the photoelectric effect was first documented in by Heinrich Hertz and later by Lenard in

Albert Einstein, a German physicist, is considered one of the greatest scientists of all times. He has contributed to the fields of general relativity , black holes, photoelectric effect, to name a few. In , Einstein was awarded the Nobel Prize in physics for the discovery of the photoelectric effect. Einstein's idea about light was revolutionary and magnificent. He gave an efficient method of irradiation.

Einstein photoelectric effect class 12

Read till the end to know more. In this article, we will understand how Einstein explained the photoelectric effect and why earlier scientists failed to do this. This concept came into the picture in the year by Heinrich Hertz. It was further researched and observed by Lenard in The photoelectric effect is a phenomenon wherein electrons get emitted from the metal when the light of substantial frequency is incident on it. Hertz believed that the wave theory would surely explain the photoelectric effect; however, it could not be due to the following reasons:. This meant that the kinetic energy of electrons would increase with that of light intensity. As energy depends on the wave theory intensity, the light of low intensity should emit electrons after some time so that the electrons can acquire a sufficient amount of energy to emit. But emission of the electron was spontaneous irrespective of the intensity of light. The wave theory says that light of any frequency must eject electrons. However, the emission of electrons only happened for frequencies greater than that of a threshold frequency v0.

Ans : The photoelectric effect was initially explained by Heinrich Hertz in the year and by Lenard in the year Discuss how it gives the concept of threshold frequency. Below this frequency, there is no electron emission.

Einsteins photoelectric equation is. Write Einstein's photoelectric equation. What is photoelectric effect? Mention the Einstein's photoelectric equation. Explain the laws of photoelectric effect from the Einstein photoelectric equation. By photoelectric effect, Einstein, proved. Define the threshold frequency v 0 and stopping potential V 0.

If you're seeing this message, it means we're having trouble loading external resources on our website. To log in and use all the features of Khan Academy, please enable JavaScript in your browser. Search for courses, skills, and videos. Einstein's Photoelectric Equation. Explaining the experiments on the photoelectric effect. How these experiments led to the idea of light behaving as a particle of energy called a photon. Key points. Based on the wave model of light, physicists predicted that increasing light amplitude would increase the kinetic energy of emitted photoelectrons, while increasing the frequency would increase measured current.

Einstein photoelectric effect class 12

The photoelectric effect is a phenomenon where electrons are emitted from the metal surface when light of sufficient frequency is incident upon it. The concept of the photoelectric effect was first documented in by Heinrich Hertz and later by Lenard in Hertz who had proved the wave theory himself did not pursue the matter as he felt sure that it could be explained by the wave theory. However, the concept failed in the following accounts:. Electrons emitted from underneath the metal surface lose some kinetic energy during the collision. But the surface electrons carry all the kinetic energy imparted by the photon and have the maximum kinetic energy. Below this frequency, there is no electron emission. Thus, the energy of a photon with this frequency must be the work function of the metal. V max is the maximum kinetic energy of the electron. It is calculated experimentally using the stopping potential.

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Hence, we can say that at threshold frequency, v0, the electrons get ejected. Zeroth law of Thermodynamics The Zeroth law of thermodynamics states that any system which is isolated from the rest will evolve so as to maximize its own internal energy. Get all the important information related to the NEET UG Examination including the process of application, important calendar dates, eligibility criteria, exam centers etc. Discuss how it gives the Download Now. A metallic strip, when exposed to light or sun, will not be able to produce the Photoelectric effect unless the frequency is greater than the threshold value. As energy depends on the wave theory intensity, the light of low intensity should emit electrons after some time so that the electrons can acquire a sufficient amount of energy to emit. Frame Einstein. The energy carried by each particle of light, known as quanta or photon, depends on the frequency v of light shown by the photoelectric effect equation. Using this equation; the value of 'h' is calculated for the Photoelectric effect. As per the model proposed by Bohr, the electron quantum leaps between the orbits. The kinetic energy of the released electrons is determined by the frequency of radiation v, not their intensity; for a certain metal, there is a frequency 0, below which no electrons are released.

In , the annus mirabilis miracle year of Physics, Albert Einstein proposed an equation to explain this effect.

Explain the terms i threshold frequency, and ii stopping potential. Hence, the work function of a metal is directly related to the threshold frequency v0. Alkali metal is usually used for exhibiting photoelectric effect. Login To View Results. A second electron emission, or so-called Auger effect, can emerge from a hole left by the electron, even if the primary photoelectron does not come out of the material. Physics Light Sources Einsteins Explaination. Electrons from the deepest part of the material are more likely to collide and come out at different speeds and speeds. An electron cannot emerge from an object when the photon energy is too low. Ans : The photoelectric effect was initially explained by Heinrich Hertz in the year and by Lenard in the year Explain the laws of photoelectric effect from the Einstein photoelectric equation. The concept of the photoelectric effect was first documented in by Heinrich Hertz and later by Lenard in Heat Energy Definition. According to Einstein:. When incident radiation on light having energy greater than the threshold value of metal hits the surface, the tightly bound electrons of the metal are set loose.