Ray 2 passes through f before reflecting parallel to the axis. Physics mcqs for class 12 with answers chapter 9 ray optics. Physics mcqs for class 12 chapter wise with answers pdf download was prepared based on latest exam pattern. Use the thin lens equation to find the distance of the image. Free pdf download of cbse physics multiple choice questions for class 12 with answers chapter 9 ray optics and optical instruments. Use the lensmakers equation to determine the focal length of a thin lens. After passing the lens, the light beam focuses in one point or a virtual focus. Convex lenses are converging lenses, and concave lenses are diverging lenses. Image formed by convex lens placed at different distances is shown in the figure.
A lens with one convex and one concave side is convexconcave or meniscus. Cylindrical lens consists of concave cylindrical lensand convex cylindrical lens that are used to examine astigmatism. We look at the image formation by these spherical lenses using ray diagrams. Weve talked a lot about convex lenses, so i thought i would do a quick video on concave lenses, although there arent as many combinations of what a concave lens can do. 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. Convex lenses, geometrical optics alevel physics tutor. 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. Because the concavity of a concave lens creates something called a focal point convex lenses have it as well, its just placed a bit more differently, and this allows light waves to focus at the focal point. Mar 03, 2019 convex and concave lenses are spherical lenses. Difference between convex and concave lens with figure. Convex lens, optical bench, light source, target image slide, lens mounts, and screen.
This report presents a lab experiment that hopes to introduce and familiarise. Difference between convex and concave lens convex vs. A concave lens is just the opposite of a convex lens. 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. Report these and other data in a nicely crafted table. Concave lenses video geometric optics khan academy. The focal length of a convex lens is positive, while that of a concave lens is negative. A convex mirror can only produce a virtual image since all reflected rays will diverge. Draw a ray diagram and use the information from the ray diagram to fill in the box.
Curvedspherical mirror a curved mirror is a mirror with a curved reflecting surface. Convex and concave lenses jonny nelson introduces an animated explanation of lenses a lens is a shaped piece of transparent glass or plastic that refracts light. Uses of the concave mirror and the convex mirror in our daily life. 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. Theory when parallel light rays pass through a thin lens, they emerge either converging or diverging. It happens due the fact that rays focus on the object and the object looks bigger than its actual size. Convex and concave lenses purpose in this experiment, you will explore the difference between convex and concave lenses and determine their focal lengths. Snc 2d light and geometric optics convex mirrors extra practice worksheet a draw a ray diagram for each to locate the image. 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. What are the uses of concave and convex lenses in daily. A lens with one convex and one concave side is convex concave or meniscus. The focal length is measured from the center of the lens to the focal point. Concave and convex lenses image formation curvature.
A for concave lens and mirror focal length is negative. This video contains the properties of concave mirror, concave lens, convex mirror and convex lens and also the types of questions, which could be asked fro. A lens with two concave surfaces is biconcave or just concave. Each mirror has a radius of curvature r which is in.
Concave and convex lens uses difference between concave. When the upper half of the lens is covered by an opaque. A thin convex lens can be characterized by its focal length f, the object distance, d o. Ray diagrams for image formation by lenses diagram.
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. Properties of the formed images by convex lens and concave. Lenses lenses are made of transparentmaterials, like glass or plastic. Move the point named focus to change the focal length. To explore the difference between convex and concave lenses and to determine their focal lengths.
Give reasons and draw a ray diagram to support your answer. Light ray rules for convex lens and concave lens are discussed. Ill be the object in this video and you need to find my image. What focal length concave lens is needed to form a virtual image 10 cm from the lens when the object is 35 cm from the lens. The surface may be either convex bulging outward or concave bulging inward. Difference between convex and concave mirror with comparison. What are the uses of concave and convex lenses in daily life. A convex lens gives a real, inverted image if the object is outside the focal length of the lens. Displaying top 8 worksheets found for concave and convex lenses. Using these rules we can find the position and properties of the image. 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.
Measure the approximate focal length of the lens by focusing a distant object onto a screen and measuring the distance from the lens to the screen using the metre stick. 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. Convex and concave lensesconvex and concave lensesconvex and concave lenses are spherical lenses. Cbse 2011 a convex lens of smaller focal length can be used as magnifying glass. Apparatus selection of lenses, collimated light source, e. Uses of convex lens,concave lens,convex mirrors,concave mirrors lenses and mirrors applications study for exams optics,physics s. One mark questions convex mirror for seeing traffic at. Curving inward, concave lenses cause light to spread out, resulting in a smaller image for the viewer. This is a fun and engaging way to practice determining the differences between concave and convex lenses. Repeat the measurement by adjusting the distance between lamphousing and the screen s to roughly about 5. Ncert cbse solutions for class 10 science chapter 10. 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.
Physics mcqs for class 12 with answers chapter 9 ray. It will give a virtual upright image if the object is within the focal length. Let us find out what are mirror and lenses, phenomenas associated with them, applications, convex lens, concave lens, convex mirror, concave mirror in the form of mcqs. Oct 23, 2019 let us find out what are mirror and lenses, phenomenas associated with them, applications, convex lens, concave lens, convex mirror, concave mirror in the form of mcqs. Conversely, the concave lenses are thinner at the centre and thicker at its edges, in structure. Simulation of image formation in concave and convex lenses. Setup the lens apparatus as shown in figure 3, using the convex lens. Fun interactive lab for california life science standard 7. Determination of the focal length of thin converging and diverging lenses using. Nov 15, 2017 on the contrary, in a concave mirror, the reflecting surface bulges inwards the main difference between a convex and concave mirror lies in the image formed by the two mirrors, i.
The lateral magnification of the mirror or lens is the ratio of the image. Parallel rays of light passing through a thin convex lens cross at the focal point of the lens. Move the tip of the object arrow to move the object. The mirror and the lens are likely to be a both concave. To create a real image with a concave mirror, the object must be outside the focal point. If one of the surfaces is flat, the lens is planoconvex or planoconcave depending on the curvature of the other surface. 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. A convex apart centre concave converging eye focal focus inwards parallel real transparent virtual lens is curved outwards on both sides. Focal length of convex lens b11 lam ka yue kenneth 6s 20 date of experiment. Ray optics and optical instruments class 12 physics mcqs pdf. Whenever a light ray hits the interface between two. Students will have fun learning about how convex and concave lens work. Since f is measured in metres m the units of lens power are m1.
To investigate the image formed by a certain thin convex lens and to determine its focal length. The curved surface forms a part of the spherical lens and the dioptric power on all axis positions is the same. No matter how far you stand from a mirror, your image appears erect and smaller than you. Light that passes through a convex lens can be focused on a surface like a screen. Uses of convex lens,concave lens,convex mirrors,concave. 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. Students will read a sentence and decide if it is describing a concave or convex lense, then glue the box in the correct column.
Concave mirrors and convex mirrors image formation, ray diagram. Curved mirrors concave and convex linkedin slideshare. When you finish the lesson, you should know how to. Convex converging and concave diverging lenses are drawn as. Uses of convex lens, concave lens, convex mirrors, concave mirrors lenses and mirrors applications study for exams optics,physics s. A convex lens enables a thing to look bigger than its actual size. Rays from a single point on a distant object arrive at the lens apart centre concave converging eye focal focus inwards parallel real transparent virtual to one. Ray box multiple white rays convex lens concave lens metric rule second convex lens optional procedure. On the contrary, the image formed by the concave lens is erect, virtual and smaller, than the object. Determination of focal length of a converging lens and mirror.
Ray 1 is parallel to the axis and reflects through f. Dec 08, 2018 the focal length of a convex lens is positive, while that of a concave lens is negative. Record p, q, and hi for four different relative positions of the object, lens and image screen. Using the five white rays from the ray box, shine the rays straight into the convex. On the contrary, in a concave mirror, the reflecting surface bulges inwards the main difference between a convex and concave mirror lies in the image formed by the two mirrors, i. Figure 315 defining points for concave and convex mirrors. Nature of images by a convex and concave lenses with ray. Of the two types of lenses convex and concave, the concave lenses are used less frequently. So just remember, concave has the word cave in it so i always imagine that its kind of caving inwards caving inwards its a little bit of an exaggerated drawing but you get. 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. Students can solve ncert class 12 physics ray optics and optical instruments mcqs pdf with answers to know their preparation level.
Concaveconvex mirror and lenses for ssc cgl, chsl, mts. One mark questions convex mirror for seeing traffic at the. Whenever a light ray hits the interface between two tr ansparent materials, generally some of the. Figure shows the virtual image formed by convex lens and real image formed by concave lens. Measure the approximate focal length of the lens by focusing a distant object onto a screen and measuring the distance. Rays parallel to the axis get reflected through a common point the focal point or focus f. Demonstration of the optics of thin convex and concave. Rays of light that pass through the lens are brought closer together they converge. It is this type of lens that is most commonly used in corrective lenses.
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