Lenses are used in cameras, telescopes, binoculars, microscopes. The physics convex lenses are converging lenses, and concave lenses are diverging lenses. How students are looking after their mental health in lockdown. Aqa gcse physics 32 light 1 aqa gcse physics 3 2light sound. Ray tracing is the technique of determining or following tracing the paths that light rays take. Its a classic example of a two lens system and overall, before we get lost in details here. When you focus a camera, you adjust the distance of the lens from the film. Choose from 500 different sets of exam questions physics practice lenses flashcards on quizlet. Revision notes physics igcse light physics notes, physics. A good example of a diverging lens is a biconcave lens, as shown in the diagram. Aqa gcse physics 32 light 1 aqa gcse physics 32light sound. See more ideas about gcse revision, science and science revision. With a converging lens, paraxial rays that are parallel to the principal axis converge to the focal point, f.
Basically there are two types of lenses, convex lenses and concave lenses. Jul 23, 2015 this happens to converging lenses when the object is placed between the lens and the principle focus. The greater the power a pair of eyeglasses or contact lenses has, the worse is the vision of the person prescribed them. A guide to support non specialists with the lenses aspects of the new edexcel gcse. The image formed in figure 7 is a real image, meaning that it can be projected. Learn exam questions physics practice lenses with free interactive flashcards. Mini physics is a participant in the amazon services llc associates program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon. Lenses are a crucial part of our modern lives, they allow us to correct peoples vision, view the stars and examine bacteria.
For lab work, students often have to estimate a line of best fit for their data points manually. Types of lenses there are different ways to classify lenses. Lenses in a photo system, the lens is most critical lenses are characterized by prime vs. Figure 8 shows how such an image would be projected onto film by a camera lens. The optical center is the point on the principal axis, midway between the center of curvatures of the lens. What i want to do now is talk about lenses, or talk about what a lens is. By using refraction, lenses can bend multiple light rays. Voiceover if i had been handed this problem on a physics test i probably would have freaked out. The focal length, f, is the distance between f and the lens. Two prisms can bend light toward the principal axis acting like a crude converging lens but. Powerpoint covering the description of images formed by convex and concave lenses.
Lenses are used in cameras, telescopes, binoculars, microscopes and corrective glasses. Diverging lenses, like those worn by people with myopia or nearsightedness, have negative refracting powers. You can work out the factor of magnifications by dividing the image height by the object height. For a magnifying glass, the image is a virtual, upright and bigger than the object b real, upright and bigger than the object. The focus of convex lenses is where rays parallel to principal axis go. This simulation can be used for olevel physics, for the topic of pressure. The light rays are refracted by the cornea onto the lens. Rays passing through the optical center are not deviated.
A powerpoint that introduces students to the tips and techniques of drawing ray diagrams for lenses. A convex lens is thicker at the centre than at the edges. Lenses in optics applications types of lenses physics. A longsighted person can read writing on a whiteboard in a classroom clearly but cannot read print in a book or newspaper sharply.
A more specialized form of lenses, spectacles appeared around the 12 th century, but it took until contemporaries of galileo and later newton to develop a decent telescope. Learn about and revise lenses, images, magnification and absorption, refraction and transmission of light with gcse bitesize physics. This looks really intimidating but its actually not that bad. Both types of lens can be used to form sharp images of a point object placed on one side of them. Gcse light revise lenses and their uses in telescopes. A comprehensive introduction to lenses and drawing ray diagrams.
Lenses are curved glasses or transparent materials. A more specialized form of lenses, spectacles appeared around the 12 th century, but it took until contemporaries of galileo and later newton to develop a decent telescope we should all like lenses. The aim of rphysics is to build a subreddit frequented by physicists, scientists, and those with a passion for physics. Ppt aqa gcse physics 32 light powerpoint presentation. A convex lens gives a real, inverted image if the object is outside the focal length of the lens. Concave mirror between focal point and mirror concave mirror beyond focal point convex mirror converging lens between focal point and mirror converging lens beyond focal point diverging lens. A real image is where the light comes together to form an image on a screen. A simple lens consists of a single piece of transparent material while compound lenses consist of several simple lenses arranged along with a common axis. Applications of physics higher tier friday 19 june 2015 morning time. However a brief survey is given here as a practical guide. The lesson goes over how to draw ray diagrams for convex lenses and covers an experiment to measure the focal length of lenses. That is, light rays from one point on the object actually cross at the location of the image and can be projected onto a screen, a piece of film, or the retina of an eye, for example. Curves outwards, causes parallel rays of light to converge to a focus. Overall, then, the formula relating the curvature of the wavefronts leaving a lens to the curvature of the wavefronts entering it is.
Physics lens physics education resources, simulations. Rays of light entering a converging lens parallel to its axis converge at its focal point f. That means we have been playing with lenses for a long time. Compound lenses thin lenses in contact a simple lens system consists of the use of only one lens as opposed to compound lens system where multiple lenses can be used with a single common axis. Diverging lenses come in a few different shapes, but all diverging lens are fatter on the edge than they are in the center. Calculator, ruler instructions tt use black ink or ballpoint pen.
Fill in the boxes at the top of this page with your name, centre number and candidate number. What are ray diagrams ray diagrams for a convex lens and a concave lens are different but to draw any ray diagram you only need to know two things 1. It will give a virtual upright image if the object is within the focal length. Keep in mind that for an object to be considered a lens it must be made of a transparent material that has an index of refraction higher than air.
Isaac physics a project designed to offer support and activities in physics problem solving to teachers and students from gcse level through to university. A lens is a curved piece of glass or plastic designed to refract light in a specific. When parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus. The distance from the center of the lens to the focal point is the lenss focal length f. Image formation by lenses 10th class physics chapter 12. It demonstrates the working principle of a hydraulic press. And think about how they transmit or refract light. Light from an object passes through the cornea which is a transparent dome like structure covering the iris. Types of lens when light is refracted it changes direction due to the change in density as it moves from air into glass or plastic. The aim of r physics is to build a subreddit frequented by physicists, scientists, and those with a passion for physics.
Geometry formulasmath formulasgcse mathsmaths algebramath. Alevel physics advancing physicslenses wikibooks, open. This gcse physics quiz about light looks at lenses. Suitable from gcse to alevel, it is colourful, concise and outlines the key concepts of this topic. Conventions in light ray diagrams for the two types of lenses convex or concave. A lens is a transmissive optical device that focuses or disperses light beams by means of refraction. Pages are intact and not marred by any notes or highlighting. Gcse physics introduction to lenses and ray diagrams. To understand ray diagrams it is important to know something about images. Larger than in size the waves wall chart is ideal for your physics classroom. A ray parallel to the principle axis of a lens will go through the focal point what is the principle axis and the focal point of a convex lens. The same sort of rules apply, just with a few modifications.
With this app, students can generate data points with varying types of scatter and predict their own bestfit line before comparing it with a computer generated one based on the least mean square method. I created it as it was relevant to our schools ip3 physics as well. Steps through the ray tracing process for both types of lenses. A lens can focus light to form an image, unlike a prism, which refracts light without. How to make a cloned sim card before i start this guide, i would like. You can go here to learn more about the refraction of light. Lenses a comprehensive introduction to lenses and drawing ray diagrams. For more about the image formed by a convex lens watch the next tutorial on this channel. Convex lenses, geometrical optics alevel physics tutor.
New gcse 91 physics unit 5 lenses teaching resources. Converging lenses, like those normally found in reading glasses, have positive refracting powers. Posts should be pertinent and generate a discussion about physics. The distance between the middle of the lens and its focal point. Convex and concave lenses lenses aqa gcse physics single. Converging lenses gcse physics doodle science youtube. This page from the physics classroom discusses the structure of. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Please choose a user flair using the edit option next to your username above irc channel.
This happens to converging lenses when the object is placed between the lens and the principle focus. Sep 05, 2016 issuu is a digital publishing platform that makes it simple to publish magazines, catalogs, newspapers, books, and more online. The two main types of lenses in physics concave and convex lenses. Experiments, as well as our own experiences, show that when light interacts with objects several times as large as its wavelength, it travels in straight lines and acts like a ray. A ray passing through the centre of a lens will go straight through. Rays of light that pass through the lens are brought closer together they converge. The principal focus, f, of a converging lens is the point to which all incident rays that are parallel to the principal axis. Most of the lenses we use in everyday life are designed to bend light rays to a specific focal point where items will be in focus clear.
Uses of lenses the uses of lenses are covered in most books covering less advanced work. Types of lens lenses ccea gcse physics single science. Ancient egyptians, babylonians, and greeks, all had a sense of basic optics. Please choose a user flair using the edit option next to your username above. Easily share your publications and get them in front of issuus. Lenses lenses refract light in such a way that an image of the light source is formed. By adjusting the crosssection areas a of the two cylinders, you only need a small amount of force at the narrow piston to exert a large. Kids learn about lenses and light in the science of physics including concave, convex, converging, diverging, focal point, meniscus, and plano lenses. Convex lenses have positive powers while concave lenses have negative powers. Lenses remembering the basics of mirrors puts you half ways towards fully understanding lenses as well.
An expanded view of the path taken by ray 1 shows the perpendiculars and the angles of incidence and refraction at both surfaces. Difference between concave and convex lens with examples. Jun 10, 2008 what is the nature of the images formed by e. If the light is converging as it leaves the lens, then it comes. Electromagnetics, waves, and optics for most people, the nearest distance that objects can be located away from the eye and still seen clearly is. All orders are dispatched within 1 working day from our uk warehouse.
The diagram below shows the cross section of a human eye. Weve talked a lot about mirrors, in particular parabolic mirrors, that reflect light. The focus of the concave lenses is where rays parallel to principal come from. The power of a meniscus lens depends on which face of the lens is the more sharply curved. Note that a converging lens has a thicker waist, whereas a diverging lens has a thinner waist. A lens can be converging convex or diverging concave. Using skills, knowledge and understanding of how science works. The principal axis is an imaginary line drawn through the center of curvatures of the lens. The simplest of these compound lens systems are two thin lenses kept in contact with each other. Isaac physics a project designed to offer support and activities in physics problem solving to teachers and students from gcse y11, through to university. It goes through formation of an image on paper using lenses, how to draw a ray diagram for a lens and culminates with image description. Complete with an activity to get students used to constructing diagrams and interpreting them.
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. A convex lens is a thinner in the middle and thicker at the edges. The overall idea of how were going to approach is this. Biomass energysolar energysolar powertypes of renewable.