[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-656808-en":3,"doc-seo-656808-105":31,"detail-sidebar-cat-0-en-105":99},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":21,"is_downloadable":21,"audit_status":21,"page_count":22,"language":23,"language_code":24,"site_id":25,"html_lang":24,"table_of_contents":26,"faqs":27,"seo_title":28,"seo_description":14,"update_tm":29,"read_time":30},656808,549758146520,"Patrick","https://ap-avatar.wpscdn.com/avatar/80002397d8c0411e94?_k=1775819394049821470",6,"Technology","GEOMETRICAL OPTICS - Lenses & Mirrors","Comprehensive notes on geometrical optics covering convex and concave lenses and mirror types, including convex mirror and concave mirror concepts. Explains core ray-diagram terminology (principal axis, principal focus, focal length, optical centre, centre of curvature) and the formation of real versus virtual images for key object positions (between f and 2f, at f, at 2f, at infinity). Derives lens power and lens formula sign conventions, introduces magnification, and describes chromatic aberration and its correction using a chromatic doublet.","GEOMETRICAL OPTICS  \n([http://www.a-levelphysicstutor.com/optics-convx-lnss.php](http://www.a-levelphysicstutor.com/optics-convx-lnss.php))  \nConvex lens  \nConcave lens  \nPlane mirror  \nConvex mirror  \nConcave mirror  \nConvex Lenses  \n\n| types | basic diagram |  | power | ray diagrams |  |\n| --- | --- | --- | --- | --- | --- |\n| lens formula | magnification |  | chromatic aberration |  |  |\n|  |  |  |  |  |  |\n\nTypes of lenses  \nAll four types of convex lens are converging lenses. That is, they bring parallel rays of light to a focus, producing a real image.  \nBasic Ray Diagram  \nThe basic ray diagram for a convex lens introduces a number of important terms:  \nprincipal axis-the line passing through the centres of curvature of the lens  \nprincipal focus-a point on the principal axis where rays of light parallel to the principal axis converge  \nfocal length-the horizontal distance between the principal focus and the optical centre of the lens  \noptical centre-an imaginary point inside a lens through which a light ray is able to travel without being deviated  \ncentre of curvature-the centre of the sphere of which the lens surface is a part  \nPower of a Lens  \nThe power P of a lens is the inverse of its focal length f. Since f is measured in metres 'm' the units of lens power are m-1 .  \nThe power also depends on the type of lens.  \nConvex lenses have positive powers.  \nConcave lenses all have negative powers.  \nFor example, a 10 cm focal length convex lens has a power of +10 m-1; while a 20 cm focal length concave lens has a power of-5 m-1 .  \nRay diagrams  \nTo understand ray diagrams it is important to know something about images. Images come in two categories :  \nreal images-are produced from actual rays of light coming to a focus (eg a film projected onto a screen)  \nvirtual images-are produced from where rays of light appear to be coming from (eg a magnifying glass image)  \nRay diagrams are constructed by taking the path of three distinct rays from a point on the object:  \nnote-the lens is considered to be so thin as to be represented by the axis of the lens(green)  \nA) a ray passing through the optical centre of the lens  \nB) a ray parallel to the principal axis, which refracts through the lens, passing through the principal focus  \nC) a ray passing through the principal focus(on the same side as the object) and being refracted through the lens, emerging parallel to the principal axis.  \nThe diagrams(below) represent the formation of an image from :  \n\n| object between f and the lens (magnifying glass)\u003Cbr>\u003Cbr>The image is the same side of the lens as the object and is upright, virtual and magnified. | object at f\u003Cbr>\u003Cbr>The image is formed at infinity from parallel rays that do not converge. Therefore no image is formed. |\n| --- | --- |\n| object between f and 2f (projector)\u003Cbr>\u003Cbr>The image is on the opposite side of the lens than the object. It is real, inverted and magnified. | object at 2f\u003Cbr>The diagram is very similar to the left one, showing the three construction rays.\u003Cbr>This time the image is the same\u003Cbr>distance behind the lens as the object is in front.\u003Cbr>As before, the image is inverted and real, but is the same size as the object. |\n| object at infinity\u003Cbr>The image is formed at the focal point of the lens. It is real, inverted and diminished in size. |  |\n\nThe Lens Formula  \nWhen using this equation a sign convention must be obeyed:  \nDistances from lenses to real objects & real images are positive.  \nDistances from lenses to imaginary objects and imaginary images are negative. Focal lengths of convex lenses are positive.  \nFocal lengths of concave lenses are negative.  \n\n| The focal length f of a lens can be found quite accurately by moving an illuminated object in front of a lens so that an image is cast on a screen.\u003Cbr>By taking readings of image and object distances for different positions, a graph can be drawn.\u003Cbr>\u003Cbr>Plotting 1/u against 1/v gives a straight line with a negative gradient. The focal leng","cbCaijjnzPrRDbxK","https://ap.wps.com/l/cbCaijjnzPrRDbxK","pdf",597459,7,1,12,"English","en",105,"# Convex lenses\n## Basic ray diagram terms\n## Power of a lens\n## Ray diagrams and image formation\n## Lens formula and sign convention\n## Magnification\n## Chromatic aberration\n# Concave lenses\n## Diverging lens overview\n## Basic ray diagram","[{\"question\":\"What are the principal focus and focal length for a lens?\",\"answer\":\"The principal focus is the point on the principal axis where rays parallel to the principal axis converge. The focal length is the horizontal distance between this focus and the optical centre of the lens.\"},{\"question\":\"How do real and virtual images differ in ray diagrams?\",\"answer\":\"Real images come from actual rays converging at a focus, while virtual images come from the apparent point where rays seem to originate when extended backward.\"},{\"question\":\"What determines lens power and why can convex and concave lenses have opposite signs?\",\"answer\":\"Lens power P is the inverse of focal length f. Since the focal length of convex lenses is taken as positive and concave lenses as negative, convex lenses have positive power while concave lenses have negative power.\"}]","GEOMETRICAL OPTICS - Lenses & Mirrors | PDF",1792971044,30,{"code":4,"msg":32,"data":33},"ok",{"site_id":25,"language":24,"slug":34,"title":13,"keywords":35,"description":14,"schema_data":36,"social_meta":93,"head_meta":95,"extra_data":97,"updated_unix":98},"geometrical-optics-lenses-mirrors","",{"@graph":37,"@context":92},[38,55,75],{"@type":39,"itemListElement":40},"BreadcrumbList",[41,45,49,52],{"item":42,"name":43,"@type":44,"position":21},"https://docshare.wps.com","Home","ListItem",{"item":46,"name":47,"@type":44,"position":48},"https://docshare.wps.com/document/","Document",2,{"item":50,"name":12,"@type":44,"position":51},"https://docshare.wps.com/document/technology/",3,{"item":53,"name":13,"@type":44,"position":54},"https://docshare.wps.com/document/geometrical-optics-lenses-mirrors/656808/",4,{"url":53,"name":13,"@type":56,"image":57,"author":62,"headline":13,"publisher":64,"fileFormat":67,"inLanguage":24,"description":14,"dateModified":68,"datePublished":69,"encodingFormat":67,"isAccessibleForFree":70,"interactionStatistic":71},"DigitalDocument",{"url":58,"@type":59,"width":60,"height":61},"https://docshare.wps.com/thumbnails/geometrical-optics-lenses-mirrors/656808.png","ImageObject",300,407,{"name":9,"@type":63},"Person",{"url":42,"name":65,"@type":66},"DocShare","Organization","application/pdf","2026-11-01","2026-10-25",true,{"@type":72,"interactionType":73,"userInteractionCount":20},"InteractionCounter",{"@type":74},"ViewAction",{"@type":76,"mainEntity":77},"FAQPage",[78,84,88],{"name":79,"@type":80,"acceptedAnswer":81},"What are the principal focus and focal length for a lens?","Question",{"text":82,"@type":83},"The principal focus is the point on the principal axis where rays parallel to the principal axis converge. The focal length is the horizontal distance between this focus and the optical centre of the lens.","Answer",{"name":85,"@type":80,"acceptedAnswer":86},"How do real and virtual images differ in ray diagrams?",{"text":87,"@type":83},"Real images come from actual rays converging at a focus, while virtual images come from the apparent point where rays seem to originate when extended backward.",{"name":89,"@type":80,"acceptedAnswer":90},"What determines lens power and why can convex and concave lenses have opposite signs?",{"text":91,"@type":83},"Lens power P is the inverse of focal length f. Since the focal length of convex lenses is taken as positive and concave lenses as negative, convex lenses have positive power while concave lenses have negative power.","https://schema.org",{"og:url":53,"og:type":94,"og:title":13,"og:site_name":65,"og:description":14},"article",{"robots":96,"canonical":53},"index,follow",{"doc_id":7,"site_id":25},1793030602,{"code":4,"msg":5,"data":100},[101,105,109,113,118,121,125,129,134,137,141],{"id":21,"doc_module":4,"doc_module_name":47,"category_name":102,"show_sort_weight":103,"slug":104},"Story & Novel",90,"story-novel",{"id":48,"doc_module":4,"doc_module_name":47,"category_name":106,"show_sort_weight":107,"slug":108},"Literature",80,"literature",{"id":54,"doc_module":4,"doc_module_name":47,"category_name":110,"show_sort_weight":111,"slug":112},"Exam",70,"exam",{"id":114,"doc_module":4,"doc_module_name":47,"category_name":115,"show_sort_weight":116,"slug":117},5,"Comic",60,"comic",{"id":11,"doc_module":4,"doc_module_name":47,"category_name":12,"show_sort_weight":119,"slug":120},50,"technology",{"id":20,"doc_module":4,"doc_module_name":47,"category_name":122,"show_sort_weight":123,"slug":124},"Healthcare",40,"healthcare",{"id":126,"doc_module":4,"doc_module_name":47,"category_name":127,"show_sort_weight":30,"slug":128},8,"Research & Report","research-report",{"id":130,"doc_module":4,"doc_module_name":47,"category_name":131,"show_sort_weight":132,"slug":133},9,"Religion & Spirituality",20,"religion-spirituality",{"id":132,"doc_module":4,"doc_module_name":47,"category_name":135,"show_sort_weight":132,"slug":136},"World Cup","world-cup",{"id":138,"doc_module":4,"doc_module_name":47,"category_name":139,"show_sort_weight":138,"slug":140},10,"Lifestyle","lifestyle",{"id":142,"doc_module":4,"doc_module_name":47,"category_name":143,"show_sort_weight":114,"slug":144},19,"General","general"]