In this article, we will learn about image formation by concave and convex lenses. For drawing ray diagrams we first consider how light rays falling on both concave and convex lens in three different ways get refracted. 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. Ray diagrams for converging lenses the physics classroom. For drawing ray diagrams we first consider how light rays falling on both concave and convex lens in three different ways get. Difference between convex and concave lens with figure. Convex lenses and ray diagrams examples, solutions. One such difference is the structure of convex lens is like, thicker at the centre and thinner at the edges. Ncert class 10 science lab manual image formation by a convex lens practical. One mark questions convex mirror for seeing traffic at. Although, may also be useful for other boardsalevel. Record p, q, and hi for four different relative positions of the object. Ncert class 10 science lab manual image formation by a.
Physics mcqs for class 12 with answers chapter 9 ray. The basic ray diagram for a convex lens introduces a number of important terms. Move the point named focus to the right side of the lens to change to a concave lens. Eight important differences between convex and concave lens are compiled in the article in tabular form. Chapter 36 lenses a powerpoint presentation by paul e. Ray diagrams for image formation by lenses diagram. Shows how to draw the ray diagrams for locating the image produced by a concave lens and a convex mirror. The lens equation 7 example 1 what image is produced by placing an object6cmaway from a convex lens of focal length3cm. Ray diagram for an object infinitely far away from the lens. In mirrors, images are formed through reflection but lenses form images through refraction. Draw a ray diagram to show how a convex lens can be used as a magnifying glass. Nature of images by a convex and concave lenses with ray. The formation of images by lenses image formation by a converging lens when the object is. Images formed by convex mirror using ray diagram 1 object is between infinity and pole a image is formed between pole and focus.
Shows how to draw ray diagrams to locate the image formed by a convex lens. Since lenses pass light through them unlike mirrors it is useful to draw a focal point on each side of the lens for ray tracing. These type of lenses can converge a beam of light coming from outside and focus it to a point on the other side. A worksheet to construct ray diagrams to show where images are formed by a converging convex lens and a diverging concave lens. Draw ray diagrams showing the image formation by a convex mirror when an object is placed a at infinity b at finite distance from the mirror. This can be substituted into the lens equation as follows. An optical lens is generally made up of two spherical surfaces. Identify the device used as a spherical mirror or lens in following cases, when the image formed is virtual and erect in each case. Pick a point on the top of the object and draw three incident rays traveling towards the lens.
Ray diagrams for convex lenses hyperphysics concepts. The image formed by a single lens can be located and sized with three principal rays. Lets explore the ray tracing technique to figure out the properties of images when things are kept in front of a concave or a convex mirror. Cbse 2011 a convex lens of smaller focal length can be used as magnifying glass. If the path of several light rays through a lens is traced, each of these light rays will intersect at a point upon refraction through the lens. Setup the lens apparatus as shown in figure 3, using the convex lens. Instructor may wish to either use the same lens specifications focal length for each lens that the groups use or varying specifications. Lenses lenses are made of transparentmaterials, like glass or plastic. Feedback greatly received particularly constructive ways to improve. A convex lens gives a real, inverted image if the object is outside the focal length of the lens. Trick to drawing ray diagrams for converging lens there is one ray of light passing through the center of the lens. This is sometimes referred to as the two rules of refraction for converging lenses.
Parallel ray diagrams locating the image of a virtual object. You can see a listing of all my videos at my websit. Snc 2d light and geometric optics convex mirrors extra practice worksheet a draw a ray diagram for each to locate the image. Any incident ray travelling parallel to the principal axis of a convex lens will refract through the lens and travel through the focal point on the opposite side. When an object is kept in between optical centre and focus in front of convex lens, draw raydiagram of image formation.
Rules for drawing ray diagram in convex and concave lens. This point is known as the focus and the distance between the centre of. Concave and convex lenses image formation curvature. Convex lenses, geometrical optics from alevel physics tutor. We look at the image formation by these spherical lenses using ray diagrams. Ray 2 goes through the center of the lens unaffected ray 3 goes through f1 and refracts parallel to the axis. To investigate the image formed by a certain thin convex lens and to determine its focal length. You are provided with a ray box, lens holder, metre rule, white screen and a lens whose focal length you are to determine. Chapter 5 ray diagrams of convex lens ray diagram rules for convex lens. Move the tip of the object arrow to move the object.
Types of diverging lenses in order for a lens to diverge light, it must be. Convex lens uses, types, magnification and function of. A convex lens and a concave lens, each having the same focal length of 25 cm, are put in contact to form a combination of lenses. Light ray rules for convex lens and concave lens are discussed. Draw a ray diagram to show the formation of the image in this position of the object with respect to the lens. Lenses ray diagram construction worksheet teaching.
Does the position of the final image in a multiple lens system found by the thin lens formula always agree with the ray diagrams. Convex lens, optical bench, light source, target image slide, lens mounts, and screen. 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. You can see a listing of all my videos at my website. It is useful for helping students learn how to create ray diagrams while the instructor gives commentary.
Convex lens uses, examples, definition, ray diagram, formula. The description is applied to the task of drawing a ray diagram for an object located beyond the 2f point of a double convex lens. This is an animated power point presentation showing the steps in drawing three rays to create the image on a ray diagram. Convex lens ray diagram, image formation, table teachoo. Ray diagram helps us to study the nature, position and relative size of the image formed by lenses. A transparent material bound by two surfaces, of which one or both surfaces are spherical, forms a lens. A lens forms an upright and diminished image of an object when the object is placed at the focal point of the given lens. The convex lens is a lens that converges rays of light that convey parallel to its principal axis i. Examples are given for converging and diverging lenses and for the cases where the object is inside and outside the principal focal length. For a convex lens, object can be kept at different positionshence, we take different casescase 1 object is placed at infinityin this case, object is kept far away from lens almost at infinite distanceso, we draw rays parallel to principal axissince ray parallel to principal axis passes through t. A convex lens ray diagram is a simple way of visualising the path that light rays take when passing through a convex lens.
For a converging lens, parallel light rays will converge to a point. What is the focal length of the convex lens and size of the image formed on the screen. You are to set up the experiment as shown in the diagram. A pdf file to print out for students to use in copying down the steps i. For a convex lens, we draw the ray diagram as follows. Converging and diverging lenses 2 2275 speedway, mail code c9000 austin, tx 78712 512 4715847 i. Move the point named focus to change the focal length. Where is the final image as shown, two converging lenses, each with a focal length of 10cm, are separated by 50cm. The lateral magnification of the mirror or lens is the ratio. Focal point and focal length ray diagram for lenses. Where will an image form if an object is placed 58 cm from the mirror.
Diagram below shows several incident rays emanating from an object each incident ray will refract through the lens the refracted rays are intersecting is. Then describe the location of the image, orientation upright or inverted of the image, the relative size of the image larger or smaller than object, and the type of image real or virtual. In every problem, draw a ray diagram to confirm your answer. Ray 1 is parallel to the axis and refracts as if from f. If the object is 12 cm tall, what will be the height of the image. Image formation by convex and concave lens ray diagrams. Rotate to landscape screen format on a mobile phone or small tablet to use the mathway widget, a free math problem solver that answers your questions with stepbystep explanations. How to draw a ray diagram from focal length, object and image heights. If those surfaces are bent outwards, the lens is called a biconvex lens or simply convex lens. Question 1 mention few applications of convex mirror.
The method of drawing ray diagrams for double convex lens is described below. Determination of focal length of a converging lens and mirror. To draw a ray diagram and find the location of the image that would be created on a screen you only need to draw two ray lines. Give reasons and draw a ray diagram to support your answer. Question 2 the image formed by a convex mirror is seen to be erect,virtual and diminished. When an object is placed in between the pole and focus of the convex lens then enlarged, erected and same side of object image is formed. Images formed by convex mirror using ray diagram class. This is explained with the help of ray diagrams as follows. A convex lens of focal length 20 cm can produce a magnified virtual as well as real image. Here are some useful rays in determining the nature of the images formed by converging and diverging lens.
The other ray of light always passes through the focal point of the lens. Image formation in a convex lens can be explained with the help of three principal rays shown in the figure. Simulation of image formation in concave and convex lenses. The description is applied to the task of drawing a ray diagram for an object located beyond the 2f point of a double convex lens 1. Convex lens is a transparent curved device that is used to refract light. Although may also be useful for other boardsalevel answer sheet available. Use lens equation to find the final image m i 2o i 2i 1 i 1o m 1 x m 2. It will give a virtual upright image if the object is within the focal length. You can use the free mathway calculator and problem. Finding the focal length of a lens using the ray box. For a convex lens, we see that ray passing through focus on left becomes parallel to principal axis after refraction for a concave lens, since focus is on the right side, it appears that ray passes through focus, and then it becomes parallel to principal axis rule 3 ray passing through optical center will emerge without deviation. They come together at a point called the principal focus.
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