Concave and convex lenses pdf

Lenses convex converging lens laws of refraction and reflection can be used to explain how lenses and mirrors operate parallel rays e. Real and virtual images in question 2, students work with the bi concave and bi convex lenses to see that they can actually make a. Leave these as points for discussion and tell them to work through the next part to find out the answers themselves. Image formation by convex and concave lens ray diagrams. The size of the image is much smaller as compared to that of the object. On the contrary, the image formed by the concave lens is erect, virtual and smaller, than the object. Displaying top 8 worksheets found for concave and convex lenses. Conversely, the concave lenses are thinner at the centre and thicker at its edges, in structure. We look at the image formation by these spherical lenses using ray diagrams. Describe the shapes of three typical converging positive thin lenses and three typical diverging. 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.

Concave and convex lens uses difference between concave. Mar 03, 2019 convex and concave lenses are spherical lenses. The converging lens is thicker at its center than at its edge. 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. Focal length f is positive for converging and negative for diverging lenses. But the nature of the image produced by a these lens depends upon the position of the object. When an object is placed at infinity, the real image is formed at the focus. Concave lenses concave lenses always produce upright, virtual images. Curved mirrors concave and convex linkedin slideshare. Define the following terms in relation to concave spherical mirror. Convex lenses are converging lenses, and concave lenses are diverging lenses. Of the two types of lenses convex and concave, the concave lenses are used less frequently. 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, ray.

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. Curving inward, concave lenses cause light to spread out, resulting in a smaller image for the viewer. Convex lenses, geometrical optics from alevel physics tutor. Concave lenses video geometric optics khan academy. Surface topography and refractive index profile dictate the deterministic functionality of a lens. 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. Image formation in a convex lens can be explained with the help of three principal rays shown in the figure. In this article, we will learn about image formation by concave and convex lenses. Generally, a convex lens forms a real image, but it can also create a virtual image when the object is. To investigate the image formed by a certain thin convex lens and to determine its focal length. In addition, you need to have a small object penny, pair of dice, etc and a large object cabinet, door, tv, etc for students to examine. What are the uses for concave lenses and convex lenses. Demonstration of the optics of thin convex and concave lenses.

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. They should try to describe any images they form in terms of magnification, upright or inverted, real or virtual. Concave and convex lenses image formation curvature. To understand ray diagrams it is important to know something about images. Conversely, a positive meniscus lens has a steeper convex surface and is thicker at the centre than at the periphery. I use simple small ones that are cheap and easy to buy. A concave lens will always produce diminished, upright and virtual image of the object in front of it.

If an object is placed in front of a convex lens, the nature of the image formed depends on where the object is placed. Light ray rules for convex lens and concave lens are discussed. 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. Oct 12, 2015 therefore, convex lenses are also called converging lenses. Difference between convex and concave lens with figure. 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. Each mirror has a radius of curvature r which is in. Slide the convex and concave lenses apart to observe the effect of a combination of two lenses. Place the convex lens in the path of the five rays.

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. To explore the difference between convex and concave lenses and to determine their focal lengths. Acces pdf light refraction and lenses answers light refraction and lenses answers eventually, you will extremely discover a additional experience and capability by. 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. For aconcave lens, the lens equation is the same but the value of fis nownegative. It can form both real and virtual images depending on where the light is coming from.

Figure 315 defining points for concave and convex mirrors. It will give a virtual upright image if the object is within the focal length. A negative meniscus lens has a steeper concave surface and is thinner at the centre than at the periphery. A convex lens gives a real, inverted image if the object is outside the focal length of the lens. Apparatus selection of lenses, collimated light source, e. This is a fun and engaging way to practice determining the differences between concave and convex lenses. If an object is placed in front of the lens at a distance less than its focal length, the image formed is upright, enlarged and virtual. 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.

Use the thin lens equation to find the distance of the image. Parallel rays of light passing through a thin convex lens cross at the focal point of the lens. In mirrors, images are formed through reflection but lenses form images through refraction. One mark questions convex mirror for seeing traffic at the. Convex and concave lenses purpose in this experiment, you will explore the difference between convex and concave lenses and determine their focal lengths. Topics youll need to understand include uses for lenses and types of lenses. Concave lenses are used for correcting myopia or shortsightedness. 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. Uses of the concave mirror and the convex mirror in our daily life.

Convex converging and concave diverging lenses are drawn as. A lens with one convex and one concave side is convex concave or meniscus. Draw a ray diagram and use the information from the ray diagram to fill in the box. Oct 24, 20 geometric optics intuition with mirrors and lenses concave convex diverging converging doc physics duration. Curvedspherical mirror a curved mirror is a mirror with a curved reflecting surface. What are the uses of concave and convex lenses in daily life. Use this quiz and worksheet to gauge your comprehension of a concave lens. Convex concave meniscus lenses can be either positive or negative, depending on the relative curvatures of the two surfaces. When an object is placed behind the center of curvature. The point where the converging rays or their extensions cross.

Convex lens uses, examples, definition, ray diagram, formula. The focal length of a convex lens is positive, while that of a concave lens is negative. They should determine from the image produced whether a lens is concave or convex. 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 polarity of most lenses reported so far, that is, either positive convex or negative. This is explained with the help of ray diagrams as follows. When a ray, passing through focus strikes concave or convex lenses, the reflected ray will pass parallel to the principal axis. The lab activity requires the use of concave and convex lenses. Convex lens, optical bench, light source, target image slide, lens mounts, and screen. Properties of the formed images by convex lens and concave. R 11 and r 2 2 are positive for convex outward surface and negative for concave surface. 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. Dec 08, 2018 eight important differences between convex and concave lens are compiled in the article in tabular form.

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. It is this type of lens that is most commonly used in corrective lenses. Theory when parallel light rays pass through a thin lens, they emerge either converging or diverging. The focal length is measured from the center of the lens to the focal point.