Eight important differences between convex and concave lens are compiled in the article in tabular form. A convex lens gives a real, inverted image if the object is outside the focal length of the lens. Students can solve ncert class 12 physics ray optics and optical instruments mcqs pdf with answers to know their preparation level. Convex converging and concave diverging lenses are drawn as. In mirrors, images are formed through reflection but lenses form images through refraction. A concave mirror of radius of curvature 20cm faces a convex mirror of radius of curvature 10cm and is 28cm from it.
A lens with one convex and one concave side is convexconcave or meniscus. Concavo convex lens which is curved inwards from one side and outwards fro. If an object is placed midway between the mirrors, find the nature and position of the image formed by reflection first at the concave mirror and then at the convex mirror. Physics mcqs for class 12 with answers chapter 9 ray. Simulation of image formation in concave and convex lenses. Ppt convex and concave lenses powerpoint presentation.
If the lens is biconvex or planoconvex, a collimated beam of light passing through the lens converges to a spot a focus behind the lens. Which can make real images, which can cast a shadow. It will give a virtual upright image if the object is within the focal length. The polarity of most lenses reported so far, that is, either positive convex or negative. 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 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. Nature of images by a convex and concave lenses with ray diagrams. In this article, we will learn about image formation by concave and convex lenses. It is very important to know the sign conventions for thin lenses and. In this experiment, you will explore the difference between convex and concave lenses and determine their focal lengths.
When light is refracted it changes direction due to the change in density as it moves from air into glass or plastic. Converging lenses are always convex in shape, which means the centre is thicker than the edges. Image formation by convex and concave lens ray diagrams. Compare a study of convex and concave lenses seeing how theyre alike and different. A thin convex lens can be characterized by its focal length f, the object distance, d o. 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. 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. To find the focal point and focal length of convex and concave lens. Parallel rays of light passing through a thin convex lens cross at the focal point of the lens. In this article, we will learn about image formation by concave and convex mirrors. This has a refractive index midway between the two glass types. Move the point named focus to change the focal length. When parallel light rays pass through a thin lens, they emerge either converging or diverging. Convex lenses are converging lenses, and concave lenses are diverging lenses.
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. A lens is a shaped piece of transparent glass or plastic that refracts. A convex lens focuses light rays, whereas a concave lens causes the light rays to diverge. Nature of images by a convex and concave lenses with ray.
To investigate the image formed by a certain thin convex lens and to determine its focal length. Rays of light that pass through the lens are brought closer together they converge. Define the following terms in relation to concave spherical mirror. Physics mcqs for class 12 chapter wise with answers pdf download was prepared based on latest exam pattern. Move the point named focus to the right side of the lens to change to a concave lens.
Jonny nelson introduces an animated explanation of lenses. 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. In any event, the glue layer is extremely thin and has little effect. However, if one of the surfaces is flat and the other convex, then it is called a planoconvex lens. Concave and convex lenses image formation curvature. Students will read a sentence and decide if it is describing a concave or convex lense, then glue the box in the correct column. Lenses concave and convex apparatus selection of lenses, collimated light source, e. Ray tracing always involves drawing three light rays. Conversely, the concave lenses are thinner at the centre and thicker at its edges, in structure. A lens is a shaped piece of transparent glass or plastic that refracts light.
Biconvex lens which is curved outwards from both the sides. 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. This is a fun and engaging way to practice determining the differences between concave and convex lenses. Ray diagrams for image formation by lenses diagram. Convex and concave lenses alevel digital teachers uganda. Each mirror has a radius of curvature r which is in. To explore the difference between convex and concave lenses and to determine their focal lengths. For aconcave lens, the lens equation is the same but the value of fis nownegative. Difference between convex and concave lens with figure. 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. Properties of the formed images by convex lens and concave.
If youre behind a web filter, please make sure that the domains. 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. Free pdf download of cbse physics multiple choice questions for class 12 with answers chapter 9 ray optics and optical instruments. This report presents a lab experiment that hopes to introduce and familiarise. This is explained with the help of ray diagrams as follows. Difference between convex and concave lens convex vs. The focal length of a convex lens is positive, while that of a concave lens is negative. The point where the converging rays or their extensions cross is the focal point of the lens. If youre seeing this message, it means were having trouble loading external resources on our website. The focal length is measured from the center of the lens to the focal. Geometric optics intuition with mirrors and lenses concave convex diverging converging. We look at the image formation by these spherical lenses using ray diagrams.
Images through lenses as real, virtual, erect or magnified definition. Convex lens uses, examples, definition, ray diagram, formula. Displaying top 8 worksheets found for concave and convex lenses. F f a diverging lens is one that refracts and diverges parallel light which appears to come from a virtual focus in front of the lens. One such difference is the structure of convex lens is like, thicker at the centre and thinner at the edges.
Convex and concave lenses convex and concave lenses convex and concave lenses are spherical lenses. Light ray rules for convex lens and concave lens are discussed. Demonstration of the optics of thin convex 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. Apparatus selection of lenses, collimated light source, e. Convex lens, optical bench, light source, target image slide, lens mounts, and screen. Use this quiz and worksheet to gauge your comprehension of a concave lens. Using these rules we can find the position and properties of the image. They are the type of lens responsible for magnification and are the most common lens used in.
Chapter 34a reflection and mirrors geometrical a powerpoint presentation by paul e. This is a combination of two lenses, one convex and the other concave. All lenses are broken into two broad groups, depending on whether they focus light at a point converging lens, or spread it out diverging lens. Lenses are used in cameras, telescopes, binoculars, microscopes and corrective glasses. Theory when parallel light rays pass through a thin lens, they emerge either converging or diverging. R 1 and r 2 are positive for convex outward surface and negative for concave surface. Investigating convex lenses is a great place to begin or continue your study of optics. Diverging lenses are always concave in shape, which means the edges are thicker than the centre. 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. Plano convex lens which is curved outwards from on side and the other side is plane. Concave mirrors are also known as a converging mirror since the rays converge after falling on the concave mirror while the convex mirrors are known as diverging mirrors as the rays diverge after falling on the convex mirror.
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. Image formation in a convex lens can be explained with the help of three principal rays shown in the figure. 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. It is this type of lens that is most commonly used in corrective lenses. Convex and concave lenses purpose in this experiment, you will explore the difference between convex and concave lenses and determine their focal lengths. Compare convex lenses to pinholes and see how they are similar and differ. Surface topography and refractive index profile dictate the deterministic functionality of a lens.
The pair are cemented together not shown using canada balsam glue. What are some of the common examples of convex lenses. One mark questions convex mirror for seeing traffic at. Convex lenses, geometrical optics from alevel physics tutor. Geometrical optics in the study of how light behaves, it is. Lets practice problems involving both the lens and magnification formulas in convex and concave lenses. Chapter 36 lenses a powerpoint presentation by paul e. Move the tip of the object arrow to move the object. Ray diagram for image formation by lenses is shown in the attached figure. Curvedspherical mirror a curved mirror is a mirror with a curved reflecting surface. 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. Topics youll need to understand include uses for lenses and types of lenses. Concave lenses concave lenses always produce upright, virtual images.
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