Introduction a concave spherical mirror is an approximation of a parabolic mirror. When the lens is free of other offaxis aberrations, the image is formed on the petzval surface. We use your linkedin profile and activity data to personalize ads and to show you more relevant ads. Image formation with converging lenses florida state university. For drawing ray diagrams we first consider how light rays falling on both concave and convex lens in three different ways get. The real image of an object placed between f and 2f from a convex lens can be seen on a screen placed at the image location. The image is upright and larger than the object, as seen in figure 10b, and so the lens is called a. If we replace the convex lens with a concave lens in the above experiment of sunlight and paper. This one factor allows a very large usage of convex mirrors. Convex lenses are converging lenses, and concave lenses are diverging lenses.
They are connected by the following relation 22 where is called a lens transformation function. Read formulas, definitions, laws from image formation by lenses here. In a concave mirror, a virtual, upright image formed when the object was behind the focus. A parabolic mirror has the property that any incident light ray parallel to the principal axis and impinging upon its surface will be reflected through a point called the focus f of the mirror. Convex lens, optical bench, light source, target image slide, lens mounts, and screen. This is because the rays of light falling parallel once reflected diverge.
As an example, a positive meniscus lens can be positioned after a planoconvex lens to shorten the focal length without decreasing optical system performance. The socalled nimrud lens is a rock crystal artifact dated to the 7th century bc. Image formation by concave and convex lenses a plus topper. To study the nature of images formed by convex and concave mirrors. In a convex mirror a virtual image formed where the light rays would intersect if they were extended behind the mirror. The following figures below illustrates the formation of image of a convex lens after refraction has taken place. Image by a convex lens for object placed at different distance from it. The fact that yis positive means that the image is erect. Concave and convex lenses image formation curvature. Convex lens is a part of chapter light in science syllbus. The process by which images are formed for lenses is the same as the process by which images are formed for plane and curved mirrors. This is explained with the help of ray diagrams as follows. A transparent material bound by two surfaces, of which one or both surfaces are spherical, forms a lens.
Ncert class 10 science lab manual image formation by a convex lens practical. Explain how an image is formed by a converging lens using ray diagrams. Learn more about the nature of the image formed by lenses by visiting byjus. Image formation by convex lens animation by youtube. Ppt convex and concave lenses powerpoint presentation. Objective the objective of this lab was to verify the lens equation and to observe the formation of images by. Give differences between a concave lens and convex lens. Jan 18, 2020 ncert class 10 science lab manual image formation by a convex lens practical. The word lens comes from lens, the latin name of the lentil, because a doubleconvex lens is lentilshaped. Convex lens definition of convex lens by the free dictionary. We will find that the light gets scattered on the paper after passing through the concave lens. Ncert class 10 science lab manual image formation by a convex.
Reflection and refraction notes the physicscatalystfree. Thousands of new, highquality pictures added every day. As you bring the object more close to the lens, we get the image all the more enlarged. Note that rays of light really do meet at the position of this image, which is why we call it a real image. A convex lens gives a real, inverted image if the object is outside the focal length of the lens. Characteristics and location of image formed by lens.
Lab6 image formation with convex lenses and concave mirrors. In this case image will form between f and 2f, image will be real,inverted,smaller than the object. Therefore, it covers are a larger field of view compared to a plane or concave mirror. Nature of images by a convex and concave lenses with ray.
It will give a virtual upright image if the object is within the focal length. Convex lens is a transparent curved device that is used to refract light. When an object is placed at a finite distance from the lens, a virtual image is formed between pole and focus of the convex lens. Is the image suspended in air at a certain point where the rays from the object is converging. A lens is something that allows light rays to pass through it and bends, or refracts, them as they do so. To find the focal length of a convex mirror using a convex lens. In this section we deal with a convex lens and its ability to form virtual images. With a concave mirror, the image may be either real or virtual. On the contrary, the image formed by the concave lens is erect, virtual and smaller, than the object. A highly diminished point sized, virtual and erect image is formed when object is at infinity by a concave lens at principal focus f1. Difference between convex and concave lens with figure. An academic counsellor will be calling you for the confirmation of your booking. The image formed is at focus, real, inverted and highly diminished. Change the distance between the lens and the candle every time and notice the image.
The experiment reciprocated what we already knew about image formation in concave and convex mirrors. The image is upright and larger than the object, as seen in figure 10b, and so the lens is called a magnifier. Image formation with converging lenses national maglab. 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. Convex, converging lenses form real images and virtual images like concave mirrors. Positive meniscus lenses have a greater curvature radius on the concave side of the lens than on the convex side, enabling formation of a real image. If image formation by a convex lens is similar to image formation by a concave mirror, describe the image formed by a light source placed at the focal point of a convex lens. Here if the object is very far away, the images formed by lenses will be all the more diminished. All about spherical lens i cbse ncert class 10 physics i by instant easy learning i pdf included this lecture contains spherical lens for class 10 students from ncert book. 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.
Infer how the amount of light that enters the eye from an object changes as the object moves closer. Converging lenses can produce both real and virtual images while diverging lenses can only produce virtual images. So let us now study the types of lenses and also the images formed by lenses. Ncert class 10 science lab manual image formation by a. Image formation by convex lens class 7 video edurev. Let \r\ be the radius of curvature, n 1 be the refractive index of the medium in which object point p is located, and n 2 be the refractive index of the medium with the spherical surface. In case of a convex lens, if we bring the object close to the lens, the size of the image keeps on increasing. Image formation by concave lens class 7 video edurev. The size of the image is smaller as compared to that of the object. Dec 08, 2018 the focal length of a convex lens is positive, while that of a concave lens is negative. If the screen is removed, would the image be still perceived. Properties of the formed images by convex lens and concave. They appear to be coming from that place, but they really arent. The concave lens always forms a virtual and erect image of smaller size than the object.
A free powerpoint ppt presentation displayed as a flash slide show on id. Objective the objective of this lab was to verify the lens equation and to observe the formation of images by convex lenses and concave mirrors. A camera lens forms a real image of a distant object. Wave optics and image formation in gravitational lensing. Nov 24, 2009 convex lens is a part of chapter light in science syllbus. The focal length of a convex lens is positive, while that of a concave lens is negative. For simple lenses this curvature is equal to approximately 23 of the lens power.
As such, the characteristics of the images formed by convex mirrors are easily predictable. To investigate the image formed by a certain thin convex lens and to determine its focal length. Simple lens, images formed by a convex lens, images formed by a concave lens, the thin lens equation, the lensmakers formula, the human eye, download 2. Have you ever used a lens to cast an image on a wall. Position, size and nature of images formed by convex lens. A positive lens creates a real image of an object at infinity a negative lens creates a virtual image of an object at infinity mit 2. Refraction and the ray model of light lesson 5 image formation by. 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. As an example, a positive meniscus lens can be positioned after a plano convex lens to shorten the focal length without decreasing optical system performance.
In mirrors, images are formed through reflection but lenses form images through refraction. Stay tuned with byjus to learn more about image formation by concave and convex lenses and explore more on physics formulas and calculators. Locate the image in a lens through ray di slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Nature of image formed by convex lens and concave lens. Describe the shapes of three typical converging positive thin lenses and three typical diverging. Let us is the incident wave from a point source in front of a thin convex lens and is the transmitted wave by the lens. Virtual image formation is mentioned towards the end of the page. Find convex lens stock images in hd and millions of other royalty free stock photos, illustrations and vectors in the shutterstock collection. Unlike concave mirrors, convex mirrors always produce images that have these characteristics. Converging lenses ray diagrams the physics classroom. Theory a concave spherical is an approximation of a parabolic mirror.
Generally, a convex lens forms a real image, but it can also create a virtual image when the object is in the middle of the focus and optical centre. If a screen is placed at a distance s2 on the opposite side of the lens, an image is formed on it. Uses of the concave mirror and the convex mirror in our daily life. 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. Consider a point source of light at point p in front of a convex surface made of glass figure \\pageindex3\. Image is point sized, highly diminished, virtual and erect. Convex means curved outward, like the underside of a spoon or the dome of a sports stadium. Have you ever used a magnifying lens to look at things far away. For drawing ray diagrams we first consider how light rays falling on both concave and convex lens in three different ways get refracted. The image is upright and larger than the object, as seen in figure \\pageindex10b\, and so the lens is called a magnifier.
Image formed by a convex lens when object is at infinityii object beyond 2f1. Ray diagram helps us to study the nature, position and relative size of the image formed by lenses. The image formed is between f2 and 2f2 on the other side of. How do convex and concave lenses compare to each other. Note the concave lens always forms a virtual and erect image of smaller. Quiz if an object is 12 cm away from a convex lens of focal length 4 cm where will the image be. Apr 11, 2020 the ray passing through the focal point becomes parallel to the principal axis after refraction by the lens. Image formation by convex and concave lens ray diagrams. Watch your students become scientists as they dig into these fascinating questions. Pdf optical images due to lenses and mirrors researchgate. Therefore, if an object is placed at a distance s1 f from a positive lens of focal length f, we will find an image distance s2 according to this formula. Virtual image is formed when the light rays appear to be originating from a point but does not actually meet. A summary of the three cases or types of image formation appears at the end of this section.
Use raytracing techniques to locate images formed by thin lenses. By drawing ray diagrams, explain the formation of image. Ppt mirrors and lenses powerpoint presentation free to. The nominal curvature 1radius of that surface is referred to as the petzval, or field curvature of the lens. Science lab manual class 10 free download pdf refraction through prism. In other cases, the image is a virtual image, which cannot be projected onto a screen.
A thin convex lens can be characterized by its focal length f, the object distance, d o. Image formation in a convex lens can be explained with the help of three principal rays shown in the figure. Convex lens convex lens convex lens convex lens convex lens lens lens lens lens lens. Virtual images are ones that cannot be formed onto a screen. Take the sheet of white paper and fold it about two or three times to make a screen. A different type of image is formed when an object, such as a persons face, is held close to a convex lens. The lentil plant also gives its name to a geometric figure some scholars argue that the archeological evidence indicates that there was widespread use of lenses in antiquity, spanning several millennia.
Explain formation of different types of images by a concave lens. Watch how the image changes when you adjust the focal length of the lens, move the object, move the lens, or move the screen. Lab6 image formation with convex lenses and concave. The concave lens is known as the diverging lens because it diverges the rays after they pass through it, the image formed by the concave lens is a virtual image because it can not be received on a screen.
Aug 19, 2011 locate the image in a lens through ray di slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. We see the image at a place where no light rays are converged. We use ray tracing to investigate different types of images that can be created by a lens. Uses of convex mirror image formation on a convex mirror. Concave and convex mirrors ray diagram for convex and. This is simulation of the ray optics involved in image formation using a convex lens. Concave mirror, convex mirror, a sheet of white paper, a welllit window, and adhesive tape. Compared to other reflective mirrors, the field of view for a convex mirror is the maximum.
Concave and convex lenses image formation types of lenses. Yes, he uses an eyepiece that has a lens that magnifies the parts of the watch. Describe with the help of a ray diagram the position, size and nature of the image formed by a concave lens when the object is placed at infinity. Take care that you draw a free hand smooth curve passing practically through all. An introduction to image formation by concave and convex lenses. The method of drawing ray diagrams for double convex lens is described below. In some circumstances, a lens forms a real image, such as when a movie projector casts an image onto a screen. Sep 26, 2015 the concave lens is known as the diverging lens because it diverges the rays after they pass through it, the image formed by the concave lens is a virtual image because it can not be received on a screen. The index of refraction for free space is exactly one.
1448 307 1122 493 301 1259 1381 1098 1451 95 498 879 199 1334 1653 602 1553 183 660 399 348 239 1009 1636 528 302 784 877 766 816 40 565 452 309 148 1293 1115