{"id":4311,"date":"2018-09-06T14:22:47","date_gmt":"2018-09-06T21:22:47","guid":{"rendered":"https:\/\/gurumuda.net\/physics\/?p=4311"},"modified":"2023-08-05T11:07:33","modified_gmt":"2023-08-05T11:07:33","slug":"equation-of-converging-convex-lens","status":"publish","type":"post","link":"https:\/\/gurumuda.net\/physics\/equation-of-converging-convex-lens.htm","title":{"rendered":"Equation of converging (convex) lens","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p align=\"justify\">Article about Equation of converging (convex) lens<\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">Before learning the equation of the convex lens, understand the sign rules of the convex lens below.<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\"><b>Sign rules of the convex lens<\/b><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">&#8211; <u>The object distance (do)<\/u><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">If an object is passed through a beam of light, then <i>the object distance<\/i> is positive.<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">&#8211; <u>The image distance (di)<\/u><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">If the beam of light passes the image, then <i>the image distance<\/i> is positive (real image). If the beam of light does not pass through the image, <i>the image distance<\/i> is negative (virtual image).<\/span><\/span><!--more--><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">&#8211; <u>The focal length (f)<\/u><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">When the beam of light passes through the focal point of the lens, the lens&#8217;s focal length is positive. Conversely, if the light beam does not pass the focal point of the lens, the focal length of the lens is negative. The focal point of the convex lens is passed through the beam of light. Therefore, the focal length of the convex lens is positive.<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">&#8211; <u>The object height (ho)<\/u><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">If the object is above the principal axis, then the object height is signed positive (object is upright). Conversely, if the object is under the principal axis of the convex lens, the object height is negative (object is inverted).<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">&#8211; <u>The image height (hi)<\/u><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">If the image is above the principal axis, the image height is positive (image is upright). If the image is below the principal axis, the image height is negative (image is inverted).<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">&#8211; <u>The magnification of image (m)<\/u><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">If the magnification of image &gt; 1, then the image size is greater than the object size. If the magnification of the image = 1, then the image size is equal to the object size. If the magnification of the image is &lt; 1, the image size is smaller than the object size.<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\"><b>The equation of the convex lens<\/b><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-medium wp-image-4313\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/09\/Equation-of-converging-convex-lens-1-300x108.png\" alt=\"Equation of converging (convex) lens 1\" width=\"300\" height=\"108\" srcset=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/sites\/28\/2018\/09\/Equation-of-converging-convex-lens-1-300x108.png 300w, https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/sites\/28\/2018\/09\/Equation-of-converging-convex-lens-1.png 312w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">s = do = the object distance, s\u2019 = di = the image distance, ho = P P\u2019 = the object height, hi = Q Q\u2019 = the image height, F<sub>1<\/sub> and F<sub>2 <\/sub>= the focal point of the converging lens.<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">The P\u2019AP triangle is similar to the Q\u2019AQ triangle. Therefore :<\/span><\/span><\/p>\n<p align=\"justify\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-4314\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/09\/Equation-of-converging-convex-lens-2.png\" alt=\"Equation of converging (convex) lens 2\" width=\"174\" height=\"44\" \/><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">Triangle BF<sub>2<\/sub>A = Q\u2019F<sub>2<\/sub>Q where the distance of AB = the object height (h) and the distance of F2A = the focal length (f) of the convex lens. Therefore :<\/span><\/span><\/p>\n<p align=\"justify\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-4315\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/09\/Equation-of-converging-convex-lens-3.png\" alt=\"Equation of converging (convex) lens 3\" width=\"175\" height=\"229\" \/><\/p>\n<p align=\"justify\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-medium wp-image-4316\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/09\/Equation-of-converging-convex-lens-4-125x300.png\" alt=\"Equation of converging (convex) lens 4\" width=\"125\" height=\"300\" srcset=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/sites\/28\/2018\/09\/Equation-of-converging-convex-lens-4-125x300.png 125w, https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/sites\/28\/2018\/09\/Equation-of-converging-convex-lens-4.png 135w\" sizes=\"auto, (max-width: 125px) 100vw, 125px\" \/><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">do = the object distance (positive if the object is passed through by the light beam)<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">di = the image distance (positive if the image is passed through by the light beam or image is real)<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">f = the focal length (positive if the focal point of the convex lens is passed through by the light beam)<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">Always remember the sign rules of the convex lenses when using this equation to solve the problem of the convex lenses.<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\"><b>The magnification of image <\/b><b>(m)<\/b><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">Observe the formation of the image above. Similar to the PAP &#8216;and QAQ&#8217; triangles, we can derive the relationship between the object distance and the image distance with the object height and the image height:<\/span><\/span><\/p>\n<p align=\"justify\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-4317\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/09\/Equation-of-converging-convex-lens-5.png\" alt=\"Equation of converging (convex) lens 5\" width=\"96\" height=\"42\" \/><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">The equation above can be written again as below by adding the symbol m:<\/span><\/span><\/p>\n<p align=\"justify\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-4318\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/09\/Equation-of-converging-convex-lens-6.png\" alt=\"Equation of converging (convex) lens 6\" width=\"116\" height=\"42\" \/><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">m = the magnification of the image<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">ho = the object height (positive if the object is above the principal axis of the convex lens or the object is upright)<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">hi = the image height (negative if the image is below the principal axis of the convex lens or the image is inverted)<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">do = the object distance (positive if the object is passed through by the light beam)<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman, serif;\"><span style=\"font-size: medium;\">di = the image distance (positive if the image is passed through the light beam or the image is real)<\/span><\/span><\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>Article about Equation of converging (convex) lens Before learning the equation of the convex lens, understand the sign rules of the convex lens below. Sign rules of the convex lens &#8211; The object distance (do) If an object is passed through a beam of light, then the object distance is positive. &#8211; The image distance &#8230; <a title=\"Equation of converging (convex) lens\" class=\"read-more\" href=\"https:\/\/gurumuda.net\/physics\/equation-of-converging-convex-lens.htm\" aria-label=\"Read more about Equation of converging (convex) lens\">Read more<\/a><\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"Equation of converging (convex) lens","_seopress_news_disabled":"","_seopress_video_disabled":"","_seopress_video":[],"_seopress_pro_schemas_manual":[],"_seopress_pro_rich_snippets_disable_all":"","_seopress_pro_rich_snippets_disable":[],"_seopress_pro_schemas":[],"footnotes":""},"categories":[2],"tags":[],"class_list":["post-4311","post","type-post","status-publish","format-standard","hentry","category-basic-physics-tutorials"],"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/4311","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/comments?post=4311"}],"version-history":[{"count":2,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/4311\/revisions"}],"predecessor-version":[{"id":8438,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/4311\/revisions\/8438"}],"wp:attachment":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/media?parent=4311"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/categories?post=4311"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/tags?post=4311"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}