A lens is a curved piece of glass or plastic designed to refract light in a specific. Types of lenses there are different ways to classify lenses. Each of a lens two faces is part of asphere and can be convex or concave if a lens is thicker at the center than theedges, it is a convex, or converging, lenssince parallel rays will be converged tomeet at the focus. We all know that the importance of mirrors, lens etc. When light falls on a highly polished surface like a mirror. You then place a converging lens between the object and the mirror. The rays of light coming from the point reflect according to. Two prisms can bend light toward the principal axis acting like a crude converging lens but. Uses of convex lens,concave lens,convex mirrors,concave mirrors lenses and mirrors applications study for exams optics, physics.
You adjust the distance of the lens from the object until a sharp image of the object is focused on the screen. When light falls on a highly polished surface like a mirror most of the light is sent back into the same medium. Jan 26, 2018 this is a highly reputed and good quality content book. Pdf the first malayali appeared in indian postal stamp. Finally, the magnification of a mirror or lens is given by the formula hh. Physics lenses are curved glasses or transparent materials. A mirror will have only one focal point, which is in front of the mirror. This book provides an introduction to the eld of optics from a physics perspective. Background in class you have studied the physics of thin.
The focus of convex lenses is where rays parallel to principal axis go. A lake with clear water and a dark bottom mirrors very well when the surface is flat no wind. Use the escape key on a keyboard or comparable method to exit from fullscreen mode. Light reflection and refraction 161 let us recall these laws i the angle of incidence is equal to the angle of reflection, and ii the incident ray, the normal to the mirror at the point of incidence and the reflected ray, all lie in the same plane.
Optics exam2 and problem solutions physics tutorials. The vision may be corrected in the diagram above by using a a. A lens is a transparent device with two curved surfaces, usually made of glass or plastic, that uses refraction to form an image of an object. Or should it be a plus sign for mirrors and minus for lenses. In this video i will introduce the objects, focal points, images of the converging and diverging lenses, and concave and convex mirrors. This property has put mirrors and lenses in use for centuries. So lets see how it goes, suppose that ive got an object out here in air and then ive got a piece of glass thats curved outward like this in a convex way. This, too, i shall ignore, except for a brief foray in section 2. A converging beam of light is incident upon the lens directed toward a virtual object o that is 60 cm from the lens.
Physics 106 lab lenses and mirrors physics dept home. Ray, coming from first mirror turns back with same path after reflecting from second mirror. Jun 16, 2016 in this video i will introduce the objects, focal points, images of the converging and diverging lenses, and concave and convex mirrors. Lenses in optics applications types of lenses physics. Geometric optics intuition with mirrors and lenses concave convex diverging converging. Mirrors and lenses both have the ability to reflect or refract light. The most apparent distinction between mirrors and lenses are that mirrors reflect light rays light bounces back while light rays are refracted passthrough through a lens. Lenses lenses refract light in such a way that an image of the light source is formed. The primary goals are to understand the relationship between image distance, object distance, and image scale.
Jan 19, 2017 get your own crash course physics mug from dftba. If the object and image are the same distance from the mirror and magnification is 1, then as the object approaches the mirror at a certain speed, the image is approaching the plane mirror at the same speed, therefore you approach the image more quickly than you approach. Especially through systems made of lensespieces of glass or plastic shaped to alter the light passing through themoptics have made possible photography. Download pdf geometrical optics kota study material for. The main development of the book begins in chapter 1 with. To the right of the lens is water refractive index 1. It seems that no two professors or teachers or books. The same strategies are valid for mirrors as for lenses with one qualificationuse the ray tracing rules for mirrors listed earlier in this section. Confused on mirrorlens sign conventions physics forums.
Finally, the magnification of a mirror or lens is given by the formula hh ss where h is. That means we have been playing with lenses for a long time. It will give a virtual upright image if the object is within the focal length. Physics 21900 general physics ii electricity, magnetism and optics lecture 19 chapter 22. A convex lens gives a real, inverted image if the object is outside the focal length of the lens. Physics study guideoptics wikibooks, open books for an. Concaveconvex mirror and lenses for ssc cgl, chsl, mts, nda, cds railway exams. As of 2010, mirrors and lenses are so prevalent that most people use them every day, regardless of whether or not they consciously perceive the use. Geometric optics converging lenses and mirrors physics lab iv objective in this set of lab exercises, the basic properties geometric optics concerning converging lenses and mirrors will be explored. Typically such a mirror is not a complete sphere, but a spherical cap a piece sliced from a larger imaginary sphere with a single cut. The text is designed for upperlevel undergraduate students with a physics background. Using the interactive the optics bench interactive is shown in the iframe below.
Lecture notes optics pdf 57p this note covers the following topics. Determination of focal length of a converging lens and mirror. Lenses and how brain adapts to the image reflected or absorbed goals at the end of the presentation the student will be able to correctly differentiate between absorption, reflection and refraction. Clickingtapping the hot spot opens the interactive in fullscreen mode. Uses of convex lens,concave lens,convex mirrors,concave. By using refraction, lenses can bend multiple light rays. It focuses primarily on the wave and ray descriptions of light, but also includes a brief introduction to the quantum description of light. Light from the object passes through the lens, reflects from the mirror, and passes back through the lens. These laws of reflection are applicable to all types of reflecting surfaces. Also, lenses have two focal points, one on each side of the lens.
Power of a convex lens is positive and that of a concave lens is negative. Frankl your own mind is a sacred enclosure into which nothing harmful can enter except by your promotion. Rotating mirror sweeps the scene until the image is aligned with fixed image from mirror m pretty much stereovision and window correlation from the manual of photography. Lenses and mirrors static web pages for physics and. Concave mirrors and convex mirrors image formation, ray diagram. It is easiest to concentrate on only three types of imagesthen remember that concave mirrors act like convex lenses, whereas convex mirrors act like concave lenses. The pdf version of the teacher toolkit on the topic of vectors is displayed below. A spherical mirror is simply a piece of a mirrored sphere. An object placed a certain distance away from a lens will produce an image at a certain distance from the lens, and the thin lens equation relates the image location to the object distance. A system of lenses andor mirrors forms an image by gathering rays from an object and then causes them to converge or diverge. When this occurs, glasses or contact lenses may be used to correct the vision causing the light to focus on the back of the eye. Lenses and depth of field prepared by behzad sajadi. I reffered 5 or six books which says that focal length of convex mirror is positive and focal length of concave mirror is negative. Figure 3 illustrates how images are formed by a plane mirror and curved mirrors.
Introduction to lenses 10th class physics chapter 12. Lenses lenses are made of transparentmaterials, like glass or plastic. Realworld connections and examples make learning physics fun while plenty of math practice problems and selfquizzes help you succeed. Mirrors, which have curved surfaces designed to reflect rays, also form images. Lenses and mirrors applications study for exams optics, physics.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. The power of a lens is defined as the reciprocal of its focal length. On the other extreme, a lens is a part of transparent refracting medium, i. Due to the viewing angle, total internal reflection is not occurring at the top edge of this image, and we can see a view of. In addition, for spherical mirrors the focal length is half the radius of curvature of the reflecting surface. Magnification produced by a lens is also related to the objectdistance u, and the imagedistance v and is given by. The circular ripple in the image center is actually on the water surface. We will talk about how these things work using the following. This equation allows you to calculate the focal length of a lens if all you know is the curvature of the two surfaces.
The physics convex lenses are converging lenses, and concave lenses are diverging lenses. Ancient egyptians, babylonians, and greeks, all had a sense of basic optics. This is true for movie projectors, cameras, and the eye. The difference between mirror and lens is that mirror means a smooth and highly polished glass surface, through which images are formed by reflection, as the light falls on it. The focal length, f, is the distance between f and the lens. With a converging lens, paraxial rays that are parallel to the principal axis converge to the focal point, f. Two concave mirrors are placed on same principal axis. Biconvex glass lens, spherical concave mirror, meter ruler, optical bench, lens holder, selfilluminated object generally a vertical arrow, screen. Therefore it has a radius, center point, circumference, etc lets make ray diagrams. Light is that range of electromagnetic energy that is visible to the human eye, the visible colors.
The physics classroom grants teachers and other users the right to print this pdf document and to download this pdf document for private use. Optics is the branch of physics concerned with the nature and uses of light. The purpose of this lab is to introduce students to some of the properties of thin lenses and mirrors. Difference between mirror and lens with comparison chart.
At the end of the presentation, the ss will be able to correctly differentiate between the three types of mirrors. The optical radiation includes not only the visible range, but a broader range of invisible electromagnetic radiation that could be influenced in its radiation behavior in a similar way as the visible radiation, but needs often other transmitters or receivers for this radiation. In this book you will find a lot of questions, solved examples and short, very short, one wors questions related to particular topic. Apply the thin lens equation and the mirror equation to determine the focal length of a converging biconvex lens and mirror. The power p of a lens of focal length f is given by. Similarly transparent plastic mirrors reasonably well when put on top of dark paper lesson 3. Keep in mind that for an object to be considered a lens it must be made of a transparent material that has an index of refraction higher than air. As all who have ever tried lens and mirror calculations know, the biggest difficulty we have to face is that of the dreaded sign conventions. One of the easiest shapes to analyze is the spherical mirror. Christmas balls, spoons, pans, windows, computer screens.
R is the radius of curvature and c 1r is the curvature of the surface. Section summary the characteristics of an image formed by a flat mirror are. Mirror, mirror on the wall eight lessons on mirrors. The same sort of rules apply, just with a few modifications. Lenses remembering the basics of mirrors puts you half ways towards fully understanding lenses as well. Kids learn about lenses and light in the science of physics including concave, convex, converging, diverging, focal point, meniscus, and plano lenses. The primary goals are to understand the relationship between. The image distance for a plane mirror is always equal to the object distance because the magnification is 1. There are two types of lenses, and they each change the perspective of how things look. And the name of this book is optics and modern physics by dc pandey.
Newtonian physics includes both action at a distance e. Ifthe outside, or convex surface, is silvered, we have a convex mirror. A ray parallel to the lens axis passes through the far focus of a converging lens or appears to come from the near focus of a diverging lens. Designing an achromatic doublet a combination of two lenses in contact, a converging lens made of crown glass and a weaker diverging lens made of flint glass, can be designed so that the combination is a converging lens that is almost achromatic. Use this method to determine f, focal length of the diverging lens as follow. Image formation for mirrors and lenses type focal length f object distance s image distance s character orientation size concave mirror converging lens f 0 s 2f f 2f real inverted enlarged s mirror diverging lens f. Jonathan is a published author and recently completed a book on physics and applied mathematics.
Then, cab and fab are approximately right triangles with the same opposite side ab. The three types of images formed by mirrors cases 1, 2, and 3 are exactly analogous to those formed by lenses, as summarized in the table at the end of image formation by lenses. The goal of the experiment is to be able to analyze ray diagrams so as to determine fundamental properties of image formation. A case 1 image is formed when do f and f is positive, as in figure 10a. Image formation by mirrors physics simple book production. In this trivia questions quiz, you will get to learn some more about the different lenses and mirrors and how they differ from each other. Lenses or mirrors with flat surfaces are said to have an infinite radius of curvature. Alevel physics, section thermal physics, 6 chapters, 34 pages, 1. Image formation by lenses physics simple book production. However, the document should not be uploaded to other servers for distribution to and or display by others. Telescopes, microscopes, cameras, projectors, your eyes, all have one thing in common. You can go here to learn more about the refraction of light. Ray hits the vertex of mirror 1 and reflects with same angle. If youre seeing this message, it means were having trouble loading external resources on our website.
May 07, 2020 just how much do you know about the different types of lenses and mirrors. Although it is possible to buy lenses that have aspherically curved surfaces, the vast majority of lenses have spherically curved surfaces. Most of the lenses we use in everyday life are designed to bend light rays to a specific focal point where items will be in focus clear. Real images, such as the one considered in the previous example, are formed by converging lenses whenever an object is farther from the lens than its focal length. A lens can focus light to form an image, unlike a prism, which refracts light without focusing. A more specialized form of lenses, spectacles appeared around the 12 th century, but it took until contemporaries of galileo and later newton to develop a decent telescope. A spherical mirror consists of a small section of the surface of a sphere with one side of the surface covered with a polished reflecting material, usually silver or aluminum. Special mirrors all kinds of shiny objects act like mirrors. Initially, i shall also make the approximation that lenses are thin. Jun 05, 2006 sir, i am confused on what sign conventions to follow. Principles and problems combines proven, comprehensive content with dynamic multimedia tools and engaging, handson labs to help you get the big ideas of physics. As of 2010, mirrors and lenses are so prevalent that most people use them every day, regardless of whether or not they consciously. A compound microscope has two convex lenses, separated by 10.
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