Dual nature of radiation and matter class 12 notes physics. The discovery of the particlelike character of light. If the frequency is halved and intensity is doubled, the photocurrent becomes. All of our visitors who are preparing for any general knowledge related written exam or interview related to the subject of physics, can prepare for it with ease by using our free online tests as a guide.
Dual nature of matter and radiation class 12 notes pdf. Questions about the dual nature of light have been. Photon, light quanta, double slit experiment, machzehnder interferometer. No electrons are emitted if the incident photon frequency is below a threshold value. Properties of cathode rays i cathode rays are not electromagnetic rays. In this modern view, they define light as a collection of one or more photons propagating through space as electromagnetic waves. Many unique properties of light are extremely fascinating.
Physics notes class 12 chapter 11 dual nature of radiation. It is a complex topic but among the most intriguing in physics. The emission of free electrons from a metal surface when the light is shone on it, it is called the photoemission or the photoelectric effect. Important notes are also helpful for revision when you have less time and have to study many topics. Anticipatory set attention grabber essential question what is the result of light hitting an objectinteracting with matter. The waveparticle duality principle of quantum physics holds that matter and light exhibit the behaviors of both waves and particles, depending upon the circumstances of the experiment. Learn vocabulary, terms, and more with flashcards, games, and other study tools. This effect led to the conclusion that light is made up of packets or quantum of energy.
Modeling concepts to teach dual nature of light speed of light light travels at the very fast speed at 3. This property makes a black body a perfect source of thermal radiation. The nature of light the electro the dual magnetic nature of light slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. The basic nature of light nature of light photon terrace. Some say it is nothing more than a wave, while others insist that light consists of lots of tiny elementary particles. It was these rays that actually caused us to see things. Since both are forms of energy so can be transformed into each other. A very good realization of a black body is an oven with a small hole, see fig. Describe the six properties of electromagnetic waves and give everyday examples. These rays are produced in a discharge tube at a pressure below 0. Light seems to have a dual natureparticlelike in some situations, wavelike in others. Important notes of physics for neet, jee for dual nature of radiation and matter are useful for all aspirants preparing for entrance exams including jee, neet.
They were found to travel with speeds ranging from about 0. Describe the dual nature of light, as a continuous wave and a discrete particle photon, and give examples of light exhibiting both natures. Although frequently associated with light, the term can be applied to many phenomena. In 1801, thomas young shined light between two adjacent slits. Physics notes class 12 chapter 11 dual nature of radiation and matter cathode rays cathode rays are the stream of fast moving electrons. Pdf light doesnt have dual nature shahab shahrabadi.
Through the researches accumulated over 2,000 years of time, the true nature of light or namely the photon was discovered. It manifests itself as a wave in diffraction, interference, polarization, etc. The properties of light can be explained by considering it as either wave or particle as follows dual nature. These notes are combined with chapter12 atoms and chapter nuclei. Put simply, it is all about the dispersal of a short light wave into free electrons and a longer wave. Now the question was whether the light quantum theory was indicative of the particle. Dual nature of light sometimes it behaves like a particle called a photon. There are four types of electron emission, namely, thermionic emission, photoelectric emission, field emission and secondary emission. It follows chapter 21 of the textbook astronomy, the dual nature of light.
From this moment, light was considered either as a. The nature of light summary the physics hypertextbook. Revealing facts of these properties may lead us to using light more effectively than ever before. The phenomenon of emission of electrons from mainly metal surfaces exposed to light energy x rays. Albert einsteins photoelectric effect experiment proves that light can behave as a particle while thomas youngs doubleslit experiment shows that it also behaves as a wave. The evidence for the description of light as waves was well established at the turn of the century when the photoelectric effect introduced firm evidence of a particle nature as well. This chapter summarizes the theories of the nature of light, including the corpuscular theory and the wave theory, developed up to the end of the nineteenth century. A complete description of the nature of light requires two explanations. Einstein were conducted to introduce the concept of quantum of light, later called photon. It expresses the inability of the classical concepts particle or wave to fully describe the behaviour of quantumscale objects. Further, the value of em was found to be independent of the nature of the materialmetal used as the cathode. Light waves can interfere with other light waves, canceling or amplifying them. Describe the dual nature of light, as a continuous wave and a discrete.
What is new is the idea that particles inherently show wavelike behavior, with similar consequences. The photon has many mysterious physical properties such as possessing the dual properties of a wave and a particle. Sometimes it behaves like a particle called a photon, which explains how light travels in straight lines 2. This video was produced for andrew mccandless honors physics class at nantucket high school in 20. Cbse class 12 physics revision notes for chapter 11 dual. Newtons contributions to optics and his emission theory are then described. Waveparticle duality publicized early in the debate about whether light was composed of particles or waves, a waveparticle dual nature soon was found to be characteristic of electrons as well. Technological applications based on the manipulations of light include lasers, holography, and fibreoptic telecommunications systems in most everyday circumstances, the properties of light can. Dual nature of light and matter printer friendly version this lesson is the outline for a speech that i gave many years ago for some middle school teachers who wanted some background on the dual nature of light and matter. Particle nature of light definition photon properties. As albert einstein wrote it seems as though we must use sometimes the one theory and sometimes the other, while at. Questions about the dual nature of light have been puzzling most physicists since more than one century, when m.
By the end of this section, you will be able to do the following. The maximum value of k is independent of the light intensity. Pdf in this paper is presented a simple alternative model of the dual nature of light, based on the deliberate inversion of the original statement. The dual nature of light means that, in some experiments, light behaves as a wave. Just pick up a cd or dvd and watch the rainbow of colors flashing off the gratings grooves, and think. As there is complete equivalence between matter mass and radiation energy and the principle of symmetry is. The wave properties of light include frequency and wavelength. This is a complete set of notes of dual nature of radiation and matter which is a part of physics syllabus for neet, jee. Waveparticle duality is the concept in quantum mechanics that every particle or quantum entity may be described as either a particle or a wave. Now it is also known that the shorter the wavelength is, the more energy is carried by the beam. Physics mcqs for class 12 with answers chapter 11 dual.
Sometimes it behaves like a wave, which explains how light bends or diffracts aro. Simple alternative model of the dual nature of light and. Chapter eleven dual nature of matternot to be republished. All chapter 11 dual nature of radiation and matter exercises questions with solutions to help you to revise complete syllabus and boost your score more in examinations. According to the wave theory proposed by christiaan huygens, light is considered to be emitted as a series of waves in all directions. As the radiation has dual nature, matter should also possess dual character. If you continue browsing the site, you agree to the use of cookies on this website. Here, we will take one step closer to the wonders of light through its wellknown basic properties. The simplest demonstration of the wave nature of light is to throw two stones into a pool of water and watch the waves from each pass through each other and emerge unchanged. Dual nature of matter and radiation class 12 notes pdf download the elementary particle in an atom having negative charge of magnitude 1. Euclid later introduced the idea of light rays as straight lines that were for him no mere geometrical fiction. This definition, which combines light s wave and particle nature, makes it possible to rethink thomas youngs doubleslit experiment in this way. Free pdf download of ncert solutions for class 12 physics chapter 11 dual nature of radiation and matter solved by expert teachers as per ncert cbse textbook guidelines. Given on this page is a free online quiz which includes mcqs questions and answers related to the topic of light.
The light waves interfered with each other and formed an alternating pattern of light and dark bands. Dual nature of radiation and matter mcq questions with answers pdf question 1. Ncert solutions for class 12 physics chapter 11 dual. Sometimes it behaves like a wave, which explains how light bends or diffracts around an object 3. Further, the value of em was found to be independent of the nature of. Experiments conducted by scientists of the time davisson, germer, thompson and others proved that electrons and other particles also had a dual nature and presented interference and diffraction properties besides their wellknown particle properties.
Incandescence is the emission of light from hot matter t. Some experiments prove that light possesses characteristics of a wave while other experiments prove light is a particle. The nature of light as a wave a small disturbance in an electric field creates a small magnetic field, which in turn creates a small electric field, and so on light propagates itself by its bootstraps. Implications for atomic structure apply uncertainty principle to e in h atom m e 9. Light is neither considered a wave nor a particle, instead it has characteristics of both a wave and a particle. The word wavelength is used to express the wave or undulating property of light. The dual nature of light refers to the fact that light can act as both a wave and a particle. Scientists accept the evidence that supports this dual nature of light even though it intuitively doesnt make sense to us. Among the many wavelike properties of light that demonstrate this are phenomena from diffraction to dispersion to the polarization of light. This chapter summarizes the theories of the nature of light, including the corpuscular theory and the wave theory, developed up to the end of the nineteenth. The dual nature of emr of discovered everyone knows that we can think of emr as a wave. This property forms the basis of the fields of optics and optical communications and a myriad of related technologies, both mature and emerging.