For each piece of evidence, outline a characteristic feature that has been observed or measured and give a short explanation of its relevance to your answer. The energy e of a photon of light is related to its frequency, f, by plancks equation. Beyond this critical angle the light doesnt leave and is totally internally reflected. Dual nature of matter and radiation class 12 notes pdf download the elementary particle in an atom having negative charge of magnitude 1. Jan 15, 2021 msomi maktaba notes za o level na a level all subjects physics chemistry biology mathematics literature civics general study geography angiculture history kiswahili commerce book keeping accounting computer economics form one form two form three form four form five and form five study notes. After einstein presented the special theory of relativity, it was established that the speed of light is an upper limit to the velocity of any object. Throughout history, there have been many attempts to measure the speed of light, such. Particle nature of light history, characteristics of. These fundamental elements of matter are point particles. Learning about a level physics students understandings of particle physics using concept mapping a in this textbook breithaupt 2008, annihilation is intro duced in the context of pet scanninga a questioned whether it was a good idea to teach particle physics at a level owing toa a 27 92a 5breithaupt j 2008 aqa physics a as.
These would record time as the car passed through the light gates and. Physics notes class 12 chapter 11 dual nature of radiation. As and alevel physics medical physics teaching guide. Conceptual ideas develop logically and sequentially, ultimately leading into the mathematics of the topics. This fact simply proves that the speed of light is greater than that of sound. As light passes from a denser medium to an optically less dense substance there is a limit to the angle that the light can leave at. Any successful theory of the nature of light must be able to explain these and. This article focuses on the physical characteristics of light and the theoretical models that describe the nature of light. This civilization produced the highest level of intellect in many branches of human thought such as mathematics, philosophy, ethics. You need a full text book which is aimed at a standard physics a level course it can be pretty much as old as you like because things like dark matter do not come into basic physics. Provides the mysteries of light, light is it a wave or a particle.
Physics module 7 dual nature of radiation and matter atoms and nuclei 304 these observations can be summarised as follows. The ray model of light describes the path of light as straight lines. Ocr as and a level physics a student book 1 pearson schools. The sensation of vision is stimulated through optic nerve. If diffraction is observed for some phenomenon, it is evidence that the phenomenon is a. Download the 5 free pdf volumes of the motion mountain physics textbook. Using the photon theory of light, we can interpret frequency and intensity of light or. This radiation shows wavelike behavior, which can be characterized by a frequency. Did you know that you can save this pdf as a word file using acrobat. Glass,water,clear plastic and air are transparent materials. In the standard model of particle physics, photons and other elementary. As well see below, there is experimental evidence for both interpretations, although they seem contradictory.
More familiar types of waves are sound, or waves on a surface of water. The aperture to the lens pupil, and therefore the intensity of light falling on the. The nature of light in that it shows waveparticle duality. Year 12 physics the nature of light matrix education. These theories and models had great explanatory power and produced useful predictions.
Light waves can interfere with other light waves, canceling or amplifying them. Ncert solutions for class 12 physics chapter 11 dual nature of radiation and matter is an essential resource material that is essential for your class 12 and entrance exam preparation. Each point source of light is a centre of disturbance from which waves spread in all directions. It consists of dual nature of radiation and matter important questions with answers, important tables, exemplary. The locus of all the particles of the medium vibrating in the same phase at a given instant is called a wavefront.
Its major themes include introductions to the fundamentals of geometrical optics, classical electromagnetic waves and the interference effects associated with those waves, and the foundational ideas of the quantum theory of light. Particle nature of light particle nature of light blackbody radiation photoelectric effect properties of photons ionizing radiation radiation damage xrays compton effect xray diffraction photons when light exchanges energy with atoms it behaves as a particle called the photon. Now that you know the relation between photoelectric effect particle nature of light it is time to discuss some of. Ocr as and a level physics a delivery guide quantum and. The best implementation of a black body is the ulbricht sphere, see figure 3. There are four types of electron emission, namely, thermionic emission, photoelectric emission, field emission and secondary emission. Each point on a wave front is a source of new disturbance, called. Page 1 of 27 notes physics wave nature of light page 2 of 27 what. Each lesson includes informative graphics, occasional animations and videos, and check your understanding sections that allow the user to practice what is taught.
Light or any electromagnetic radiation is a stream of particles called photons. The photoelectric effect can be explained with a wave model for light and a quantum. Light is a form of energy which is given by luminous objects. Canon technology canon science lab light is it a wave. Sep 03, 2018 a photon is a particle of light defined as a discrete bundle or quantum of electromagnetic or light energy. Prior to the 20th century, physicists, including newton and maxwell, developed theories and models about mechanics, electricity and magnetism and the nature of matter. Therefore the amount of energy a light wave contains should depend on its intensity or brightness. Several activities can reinforce the idea from gcse that a wave transfers energy. Contrarily, wave nature is prominent when seen in the field of propagation of light. Nature of light light is a kind of energy that travels in waves.
Dual nature of matter and radiation class 12 notes pdf. The scientific study of the behavior of light is called optics and covers reflection of light by a mirror or other object, refraction by a lens or prism, diffraction of light as it passes by the edge of an opaque object, and interference patterns resulting from diffraction. Cambridge a level physics textbook pdf free pdf books. They played key role in shaping the physics of the coming centuries. Pressure in liquids, viscosity, bernoullis equation, density, flow properties.
Physics a level okehampton college 6 june 2018 activity 4. By suitably heating, suf ficient ther mal ener gy can be imparted to the free electrons to enable them to come out of the metal. If you shine light, or other types of em radiation, through a series of small slits the waves interfere causing constructive interference at certain points. Describe the dual nature of light, as a continuous wave and a discrete particle photon, and give examples. Indeed, the marriage of quantum mechanics the physics of the very small with general relativity the physics of the very large is believed by some to be the crucial step in formulating a general theory of everything that will hopefully contain all the basic laws of nature in one package. Enjoy an entertaining and free pdf book on physics, the science of motion. This confusion about the true nature of light continued for some years till a modern quantum theory of light emerged in which light is neither a wave nor a particle the new theory reconciles the particle properties of light with the wave nature.
This civilization produced the highest level of intellect in many branches of human thought such as mathematics, phil. This property forms the basis of the fields of optics and optical communications and a myriad of related technologies, both mature and emerging. In practice, because the speed of light is so great, the data would have to be known to impractically high. The speed of light is one of the most important constants of nature. Energy of the beam of light is localised to each photon, not spread across the wavefront of the light beam. Contents nature of light newtons rings wave theory of light 4. We can then use this method to calculate the wavelength of the light. The mathematics of a theory constitutes the entire theory. This wave property of light explains many phenomena. Ncert solutions class 12 physics chapter 11 dual nature of. Lecture 31 physics of light lecture 32 interaction of light with matter lecture 33 interference and diffraction lecture 34 the particle nature of light lecture 35 geometrical optics lecture 36 heat i lecture 37 heat ii lecture 38 heat iii lecture 39 special relativity i. Towards the same period at the end of 19th century, experimental investigations on conduction of electricity.
The propagation of light the index of refraction of a material is \n \fraccv\, where v is the speed of light in a material and c is the speed of light in a vacuum. Light and other forms of electromagnetic radiation move through a vacuum with a constant speed, c, of 2. The physics classroom tutorial presents physics concepts and principles in an easytounderstand language. Photons travel at the vacuum speed of light more commonly just called the speed of light of c 2. Walker, jearl fundamentals of physics jearl walker, david halliday, robert resnick10th edition. This theory is called huygens wave theory of light. Understanding the nature of scientific knowledge 1.
By applying a very strong electric field of the order of 108 v m1 to a metal, electrons can be pulled out of the metal, as in a spark plug. One radian rad is defined as the angle subtended at the centre of a circle by an arc equal in length to the radius of the circle the angular speed is defined as the rate of change of angular displacement figure 7. At that time einstein personally favored an atomistic view of light in. Light is a form of energy emitted by set of luminous body and travels along the straight line. These rays are produced in a discharge tube at a pressure below 0. If one knows the distance to the location of the lightning and the speed of sound, one could, in principle, determine the speed of light from the data. Physics notes class 12 chapter 11 dual nature of radiation and matter cathode rays cathode rays are the stream of fast moving electrons. Ncert solution of class 12 physics chapter 11 eases your work of notes preparation and revision. The wave nature of light b the particle nature of light c the wave properties of an electron d the atomic structure. Physics mcqs for class 12 with answers chapter 11 dual. The most fundamental constructs in physics are particles manifest in highenergy experiments. 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. The particle nature of light in the late 17 th century, hooke and huygens independently proposed that light was emitted in waves, with hooke suggesting that the vibrations were perpendicular to the direction of propagation, i.
Waves and particle nature of light notes this work by pmt education is licensed under cc byncnd 4. This theory on the true nature of light and human vision will help. Technological applications based on the manipulations of light include lasers, holography, and fibreoptic telecommunications systems in most everyday circumstances, the properties of light can be. Ocr asa level physics a answers to student book 1 questions. It can travel through a vacuum and many other media.
Use of the polaroid to demonstrate the transverse nature of visible light. Isbn 9781118230725 extended edition binderready version isbn 9781118230619 extended edition 1. This physics textbook is designed to support my personal teaching activities at duke university, in particular teaching its physics 141142, 151152, or 161162 series introduc tory physics for life science majors, engineers, or potential physics majors, respectively. As and alevel physics turning points in physics teaching guide. Chapter eleven dual nature of matternot to be republished. Photons are always in motion and, in a vacuum a completely empty space, have a constant speed of light to all observers. Please write clearly, in block capitals, to allow character computer recognition.
Now, wave motion was well understood, so it was expected that light waves would behave. Matter is, at the fundamental level, wavelike in nature. Introduction to the major laws of physics thoughtco. The part of optics dealing with the ray aspect of light is. Other objects which do not give out light are called non luminous objects. Oct 16, 2017 physics notes for competitive exams optics. Motion mountain the captivating free physics pdf book. The part of optics dealing with the ray aspect of light is called geometric optics.
Introduction to a level physics okehampton college. During a molecular, atomic or nuclear transition to a lower en. Mathematical elegance is the most important attribute of a theory. It is also why dvds and cds make beautiful rainbows. Motion 4 a car is travelling on a level road at a speed of 15. In 1678, dutch physicist christian huygens proposed a theory to explain the wave nature of light. Work, power, energy mechanics circular motion alevel mechanics the mechanical property of matter, hookes law alevel mechanics moments, couple alevel mechanics simple harmonic motiona level surface tension. Properties of cathode rays i cathode rays are not electromagnetic rays.
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