Table of Contents
What are the laws of photoelectric effect?
Solution : Laws of photoelectric effect: • For a given frequency of incident light, the number of photoelectrons emitted is directly proportional to the intensity of the incident light. The saturation current is also directly proportional to the intensity of incident light.
What is photoelectric effect PDF?
Photoelectric effect is the process of emitting the. electrons from the a metal surface when the. metal surface is exposed to an electromagnetic. radiation of sufficiently high frequency.
What is photoelectric effect Class 11 Ncert?
“The phenomenon of ejection of electrons from the surface of a metal when light of suitable frequency strikes on it, is called photoelectric effect. The emitted electrons are called photoelectrons.”
How did Einstein explain the law of photoelectric effect?
Since light is bundled up into photons, Einstein theorized that when a photon falls on the surface of a metal, the entire photon’s energy is transferred to the electron. A part of this energy is used to remove the electron from the metal atom’s grasp and the rest is given to the ejected electron as kinetic energy.
What is first law of photoelectric effect?
(i) There is a definite cut off value of frequency below which electrons cannot be ejected by any substance. (ii) Number of emitted electrons are directly proportional to the intensity of light incident. (iii) Kinetic energy of emitted electrons depends on the frequency of incident light on substance.
What is photoelectric effect state the laws of photoelectric emission?
When the radiation such as γ-rays, X-rays, UV and even visible light fall on metals, electrons are emitted. This, phenomenon of emission of electrons is known as photoelectric effect.
Who explained photoelectric effect?
And increasing the frequency of the light produced electrons with higher energies, but without increasing the number produced. This became known as the photoelectric effect, and it would be understood in 1905 by a young scientist named Albert Einstein.
What is meant by Compton effect?
Compton effect, increase in wavelength of X-rays and other energetic electromagnetic radiations that have been elastically scattered by electrons; it is a principal way in which radiant energy is absorbed in matter.
What is photoelectric effect HSC 12?
Solution. The ejection of electrons from a metal plate when illuminated by light or any other electromagnetic radiation of a suitable wavelength (or frequency) is called the photoelectric effect.
Who discovered the law of photoelectric effect?
The photoelectric effect was discovered in 1887 by the German physicist Heinrich Rudolf Hertz.
What is the value of 1 Einstein?
The einstein (symbol E) is a unit defined as the energy in one mole of photons (6.022×1023 photons).
What are the laws of photoelectric emission class 12?
1) The emission of electrons from the surface stops after a certain frequency known as the threshold frequency. 2) The number of electrons that are emitted from the surface is directly proportional to the intensity of the incident light.
What is the photoelectric effect?
When an electron in a material absorbs a high enough energy photon, it gains enough kinetic energy to escape from the substance. This is called the photoelectric effect. Einstein’s theory predicts that the kinetic energy E of the electron
What is the relationship between threshold frequency and photoelectric current?
The threshold frequency varies with material, it is different for different materials. The photoelectric current is directly proportional to the light intensity. The kinetic energy of the photoelectrons is directly proportional to the light frequency. The stopping potential is directly proportional to the frequency and the process is instantaneous.
When was the photoelectric effect discovered?
BACKGROUND: Historical Note:The photoelectric effect was accidentally discovered by Heinrich Hertz in 1887 during the course of the experiment that discovered radio waves.
Is the photoelectric effect constant for a specific metal?
It is constant for a specific metal but may be different for different metals. If γ = frequency of incident photon and γth= threshold frequency, then, If γ < γTh, there will be no ejection of photoelectron and, therefore, no photoelectric effect.