Describe the shapes of three typical converging positive thin lenses and three typical diverging negative. Lenses are used in all optical instruments, like microscopes, telescopes, cameras, projectors etc. A lens changes the direction of light waves by refraction. Physics mcqs for class 12 chapter wise with answers pdf download was prepared based on latest exam pattern. Oct 24, 20 geometric optics intuition with mirrors and lenses concave convex diverging converging doc physics duration. In this case the convex lens acts as if a convex mirror. Date qatar international school science department extension lesson ideas lenses lenses. Geometrical optics in the study of how light behaves, it is. The focal length is measured from the center of the lens to the focal point.
Convex and concave lenses purpose in this experiment, you will explore the difference between convex and concave lenses and determine their focal lengths. A thin convex lens can be characterized by its focal length f, the object distance, d o. Convex lenses are also known as converging lens since the rays converge after falling on the convex lens while the concave lenses are known as diverging lenses as the rays diverge after falling on the concave lens. Curvedspherical mirror a curved mirror is a mirror with a curved reflecting surface.
Dec 18, 2010 for an illustrated example of how images are formed with a convex lens, click here we have written many articles about lenses for universe today. If youre seeing this message, it means were having trouble loading external resources on our website. Convex lens, optical bench, light source, target image slide, lens mounts, and screen. The video in english explains about different types of mirror i. Convex, converging lenses form real images and virtual images like concave mirrors. In this lesson, youll learn about both concave and convex lenses. As a guideline, biconvex lenses perform with minimum aberration at conjugate ratios between 5. The same sort of rules apply, just with a few modifications. Move the point named focus to the right side of the lens to change to a concave lens. Lenses concave and convex apparatus selection of lenses, collimated light source, e. Concave lenses geometric optics physics khan academy. He handled her defense himself, eventually winning her acquittal.
In this activity you will look at only two kinds of lenses, convex and concave, and observe their similarities and differences. 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. Level 5 explain how a camera lens works level 6 relate the shape of a lens to the type of glasses needed for long and shortsightedness. Biconvex double convex lenses have the same radius of curvature on both sides of the lens and function similarly to planoconvex lenses by focusing parallel rays of light to a single point. Tippens, professor of physics southern polytechnic state university.
In 1611, kepler improved on galileos telescope by replacing its concave eyepiece with a convex one. The line through the centre of the lens is called the principle axis. A lens is a piece of transparent material typically with at least one curved surface, which refracts, or bends, light rays coming from an object. Contact lenses that correct for farsighted vision problems are also convex. Mar 04, 2015 is an educational software that helps students develop flexible knowledge, effective problem solving skills, selfdirected learning, intrinsic motivation. Convex a convex lens is one where the center of the lens is thicker than the edges. Convex and concave displaying top 8 worksheets found for this concept some of the worksheets for this concept are concaveconvex s1 identifying shapes, convex concave polygons 1, diverging converging lens work, 6 introduction to polygons, physical science 2014 2015 concave and convex mirrors, 04, polygons quadrilaterals and special parallelograms, 1 1 1 h d i i in every. While some of them are thicker at edges than at the middle, these are known as a concave lens. Lenses convex concave optical instruments mirrors convex concave. What are the uses for concave lenses and convex lenses. The following points are noteworthy, so far as the difference between convex and concave lens is concerned. See more ideas about teaching science, science activities and science lessons. It shows how rays change its path after passing through lens. Lenses remembering the basics of mirrors puts you half ways towards fully understanding lenses as well.
Difference between convex and concave lens with figure. A convex lens is a converging lens when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus. Students can solve ncert class 12 physics ray optics and optical instruments mcqs pdf with answers to know their preparation level. Science what are concave and convex lenses and prism. Frankl your own mind is a sacred enclosure into which nothing harmful can enter except by your promotion. Investigating convex lenses is a great place to begin or continue your study of optics. Concave and convex lenses image formation curvature. Mirror used in supermarkets convex mirrors lens used as rear view mirrors convex mirror mirror used as streetlight reflectors convex mirrors mirror used in making lenses of sunglasses convex mirror mirror used in headlights of cars and other vehicles concave mirror mirror used in torch light concave mirror. Continue to move the lens away from the lamp housing until a sharp image is formed on screen again. Science plane, concave and convex mirrors and reflection. In convex lenses, an object that is further away from the lenses focal length produces a real and inverted image on the other side of the lens because. Lets practice problems involving both the lens and magnification formulas in convex and concave lenses.
The top countries of suppliers are india, china, and india, from which the percentage of concave convex lenses supply is 1%, 99%, and 1% respectively. A wide variety of concave convex lenses options are available to you, there are 1,044 suppliers who sells concave convex lenses on, mainly located in asia. Lenses are transparent objects with a curved surface. A magnifying glass is another example of a convex lens. A lens is a polished piece of glass or transparent plastic with curved surfaces. Convex lenses have a significant drawback when used in optical. Convex lens screen purpose to determine the focal length of a thin lens and to explore the difference between convex and concave lenses and to determine their focal lengths. Which can make real images, which can cast a shadow. As it curves outward, it brings light together, making images appear larger. These lenses focus the rays of light to produce a apart centre concave converging eye focal focus inwards parallel real transparent virtual image that can be projected onto a screen. Concave lenses, though, serve an important role as well.
Determining focal lengths of concave and convex lenses. Demonstration of the optics of thin convex and concave lenses. The lens which merges the light rays at a particular point, that travels through it, are a convex lens. Parallel rays of light passing through a thin convex lens cross at the focal point of the lens. Convex lens uses, examples, definition, ray diagram, formula. By curving the lens in a specific way, it is possible to bend beams of light according to specific requirements. Chapter 36 lenses a powerpoint presentation by paul e. It is true that the primary lens used in binoculars and telescopes is a convex lens, but concave lenses are also involved. It shows how rays change its path after passing through lens i. Optical centre is where the principle axis meets the.
If those surfaces are bent outwards, the lens is called a biconvex lens or simply convex lens. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Feb 26, 2016 this experiment yielded an acceptable experimental values of focal lengths of both concave and convex lenses relative to the theoretical value. In other words, the edges of the lens are thicker than the middle. Kids learn about lenses and light in the science of physics including concave, convex, converging, diverging, focal point, meniscus, and plano lenses. Hello, bodhaguru learning proudly presents an animated video in english which explains about different types of lens. To find the focal point and focal length of convex and concave lens. Image formation images can be formed by lenses that. A lens that is thicker at the middle than at the edges. Jun 05, 20 lenses lenses are made of transparentmaterials, like glass or plastic. Due to the law of refraction, light rays bend as they enter and leave the lens.
Physics mcqs for class 12 with answers chapter 9 ray. If youre behind a web filter, please make sure that the domains. Some of the worksheets for this concept are diverging converging lens work, concaveconvex s1 identifying shapes, converging diverging lenses ray diagrams, name box score date ap physics work 14 chapter 24, refraction convex and concave lenses, exploration of optics converging and diverging lenses. A lens is a transmissive optical device that focuses or disperses a light beam by means of. Camera lenses are convex, as they focus all rays of light onto the subject being photographed to make that subject appear clearer. Cases of formation of images by convex lens converging lens when the position of the object is very far, the position of the image is at the focus, the formed image will be real and very tiny dot when the position of the object is at a distance greater than the double twice of the focal length, after the center of curvature, the position of the image is between the focus. Rays of light that pass through the lens are brought closer together they converge. Convex and concave lenses 1 convex and concave lenses convex lens concave lens 2 refraction by a convex lens 3 focal length of a convex lens 4 long short focal length 5 focal length of a concave lens 6 formation of a real image 7 formation of a virtual image 8 drawing ray diagrams real image important. Concave lenses video geometric optics khan academy. A lens with one convex and one concave side is convex concave or meniscus.
Uses of convex lens,concave lens,convex mirrors,concave. You will find that some lenses are thicker in the middle than at the edges and are known as a convex lens. Image formation lenses convex converging lens laws of refraction and reflection can be used to explain how lenses and mirrors operate parallel rays e. It is this type of lens that is most commonly used in corrective lenses. Properties of the formed images by convex lens and concave. In this article, we will learn about image formation by concave and convex lenses. Candidates abound for the honor of inventing the telescope, around 1600. View and download powerpoint presentations on concave and convex lens ppt.
They should try to describe any images they form in terms of magnification, upright or inverted, real or virtual. Images can be formed by lenses that divert light rays by refraction. Lenses are used in cameras, telescopes, binoculars, microscopes and corrective glasses. Types of diverging lenses in order for a lens to diverge light, it must be thinner near the midpoint to allow more bending. Move the point named focus to change the focal length. Most devices that control light have one or more lenses in them some use only mirrors, which can do most of the same things that lenses can do. Record the new position of the lens d2 4 focal length of convex lens b11. Geometric optics intuition with mirrors and lenses concave convex diverging converging doc physics duration. Quiz if an object is 12 cm away from a convex lens of focal length 4 cm where will the image be. A lens can be defined as a transparent material like a glass that has either an open curved surface or one flat surface or two curved surfaces. Image formation images can be formed by lenses that divert. Ppt convex and concave lenses powerpoint presentation. Compare a study of convex and concave lenses seeing how theyre alike and different. A convex lens focuses light rays, whereas a concave lens causes the light rays to diverge.
The focal length is measured from the center of the lens. Types of contact lenses and their characteristics1 the basic categories of contact lenses currently in use are the original hard polymethylmethacrylate pmma lenses, soft hydrogels hydroxymethylmethacrylate hema and other materials, and gaspermeable hard lenses cellulose hard pmma lenses as discussed in the previous chapter, hard. Light and optics truefalse decide whether each of the following statements is true or false. A convex lens is thicker in the middle than it is at the edges. A concave lens is any lens that has an inward curve in the middle. Simulation of image formation in concave and convex lenses. 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. Free pdf download of cbse physics multiple choice questions for class 12 with answers chapter 9 ray optics and optical instruments. This point is known as the focus and the distance between the centre of the lens to the focus is called the focal length of convex lens. A convex lens is converging and can produce virtual and real images.
Chapter 34a reflection and mirrors geometrical a powerpoint presentation by paul e. A convex lens is a converging lens when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus the distance between the principal focus and the centre of the lens is called the focal length. A convex lens is also called a converging lens because it makes parallel light rays passing through it bend inward and meet converge at a spot. What are the uses of concave and convex lenses in daily. A lens which is thinner in the centerthan the edges is. These type of lenses can converge a beam of light coming from outside and focus it to a point on the other side. Difference between convex and concave lens convex vs. If the lens is biconvex or plano convex, a collimated beam of light passing through the lens converges to a spot a focus behind the lens. Well explore how these types of lenses bend light to help people see things both near and far more clearly. It explains about properties of different types of mir. Concave, diverging lenses only form virtual images, like convex mirrors. Find powerpoint presentations and slides using the power of, find free presentations research about concave and convex lens ppt.
Archived from the original pdf on 23 november 2009. We have another rule, that when the curvature center c is on the same side of the outgoing ray, then the radius is positive. A convex lenses refracts these parallel rays so that they are come together at a point called the principal. Convex lens converging lens concave lens diverging lens convex lens a convex lens is shaped like two half circles, thin at the edge and thick at the middle. Jul 04, 2018 they, concave lenses, are useful, amongst other uses, for correcting short sightedness. The converging lens is thicker at its center than at its edge. Dec 08, 2018 the following points are noteworthy, so far as the difference between convex and concave lens is concerned. What is the focal length of the lens, and is it convex or concave.
Concave and convex lenses the type of lenses which converge the light beam coming from the source to one point on the other side to form an image is called as a convex lens, while the concave lens which is thinner at the centre and gets thicker as we move towards the edges is called as concave lens. Final quiz solutions to exercises solutions to quizzes the full range of these packages and some instructions, should they be required, can be obtained from our web page mathematics support materials. Theory when parallel light rays pass through a thin lens, they emerge either converging or diverging. Compare convex lenses to pinholes and see how they are similar and differ. To explore the difference between convex and concave lenses and to determine their focal lengths. We look at the image formation by these spherical lenses using ray diagrams.
Incidentally, keplers mother, katharina, was accused of witchcraft in 1615, when she was about 70. Keep in mind that for an object to be considered a lens it must be made of a transparent material. Lenses have focal points on either side because light shines through either side. The university of virginias biology department notes that refracting telescopes use two convex lenses and reflecting telescopes use convex and concave lenses and a flat mirror to magnify. There are two main shapes of lenses, convex and concave. Geometrical optics mirror and lenses outline reflection plane mirrors concave convex mirrors refraction lenses dispersion. The lens which disperses the light rays around, that hits the lenses, are called a concave lens. Displaying top 8 worksheets found for concave and convex lenses. Concave lenses if youre seeing this message, it means were having trouble loading external resources on our website. Take them off and look through them at halfarm length.
The focus point is on the another side of optical center. Now try finding a convex lens and place it in the path of sunrays. When you look through a magnifying glass, or take a picture with a camera, you are using a lens. Move the tip of the object arrow to move the object. To investigate the image formed by a certain thin convex lens and to determine its focal length. Convex mirror for a convex mirror, the radius of curvature is inside the mirror. Convex lenses produces converging ray lights while concave lenses produces diverging ray lights. These were primitive planoconvex lenses initially made by cutting a glass sphere in half.
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