{"id":93125,"date":"2025-06-01T11:42:22","date_gmt":"2025-06-01T11:42:22","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=93125"},"modified":"2025-06-01T11:42:22","modified_gmt":"2025-06-01T11:42:22","slug":"the-blue-colour-of-the-sky-and-the-reddening-of-the-sun-at-sunrise-and","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/the-blue-colour-of-the-sky-and-the-reddening-of-the-sun-at-sunrise-and\/","title":{"rendered":"The blue colour of the sky and the reddening of the Sun at sunrise and"},"content":{"rendered":"

The blue colour of the sky and the reddening of the Sun at sunrise and sunset are caused due to the phenomenon of :<\/p>\n

[amp_mcq option1=”dispersion of light.” option2=”reflection and refraction of light.” option3=”aberration of light.” option4=”scattering of light.” correct=”option4″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC CISF-AC-EXE – 2022<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nThe blue colour of the sky and the reddening of the Sun at sunrise and sunset are classic examples of the phenomenon of scattering of light by particles in the atmosphere.
\nWhen sunlight enters the Earth’s atmosphere, it interacts with the gas molecules (mainly Nitrogen and Oxygen) and tiny particles present. This interaction causes the light to be scattered in various directions. This process is called scattering.
\nRayleigh scattering explains why the sky is blue. It states that the intensity of scattered light is inversely proportional to the fourth power of the wavelength. Shorter wavelengths, like blue and violet light, are scattered much more effectively than longer wavelengths, like red and orange light. When we look at the sky during the day, we see the scattered blue light from all directions.
\nAt sunrise and sunset, the sunlight travels a much longer path through the atmosphere to reach our eyes. During this long journey, most of the shorter wavelength blue and green light is scattered away by the atmospheric particles. The longer wavelength light, such as red and orange, which is scattered less, is left to reach our eyes, making the Sun and the sky around it appear reddish or orange.
\n<\/section>\n
\n– The colour of the sky and the Sun’s colour at sunrise\/sunset are due to the interaction of sunlight with atmospheric particles.
\n– This interaction involves scattering of light.
\n– Shorter wavelengths (blue) are scattered more effectively than longer wavelengths (red) by atmospheric gases (Rayleigh scattering).
\n– The path length of sunlight through the atmosphere affects which colours are predominantly seen.
\n<\/section>\n
\nDispersion of light is the splitting of white light into its constituent colours (spectrum) due to the dependence of refractive index on wavelength (e.g., prism). Reflection is the bouncing of light off a surface. Refraction is the bending of light as it passes from one medium to another. Aberration refers to defects in image formation by optical systems. None of these fully explain the blue sky or red sunrise\/sunset phenomenon, which is primarily a scattering effect.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

The blue colour of the sky and the reddening of the Sun at sunrise and sunset are caused due to the phenomenon of : [amp_mcq option1=”dispersion of light.” option2=”reflection and refraction of light.” option3=”aberration of light.” option4=”scattering of light.” correct=”option4″] This question was previously asked in UPSC CISF-AC-EXE – 2022 Download PDFAttempt Online The blue … <\/p>\n

Detailed SolutionThe blue colour of the sky and the reddening of the Sun at sunrise and<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1089],"tags":[1108,1153,1128],"class_list":["post-93125","post","type-post","status-publish","format-standard","hentry","category-upsc-cisf-ac-exe","tag-1108","tag-optics","tag-physics","no-featured-image-padding"],"yoast_head":"\nThe blue colour of the sky and the reddening of the Sun at sunrise and<\/title>\n<meta name=\"description\" content=\"The blue colour of the sky and the reddening of the Sun at sunrise and sunset are classic examples of the phenomenon of scattering of light by particles in the atmosphere. When sunlight enters the Earth's atmosphere, it interacts with the gas molecules (mainly Nitrogen and Oxygen) and tiny particles present. This interaction causes the light to be scattered in various directions. This process is called scattering. Rayleigh scattering explains why the sky is blue. It states that the intensity of scattered light is inversely proportional to the fourth power of the wavelength. Shorter wavelengths, like blue and violet light, are scattered much more effectively than longer wavelengths, like red and orange light. When we look at the sky during the day, we see the scattered blue light from all directions. At sunrise and sunset, the sunlight travels a much longer path through the atmosphere to reach our eyes. During this long journey, most of the shorter wavelength blue and green light is scattered away by the atmospheric particles. The longer wavelength light, such as red and orange, which is scattered less, is left to reach our eyes, making the Sun and the sky around it appear reddish or orange. - The colour of the sky and the Sun's colour at sunrise\/sunset are due to the interaction of sunlight with atmospheric particles. - This interaction involves scattering of light. - Shorter wavelengths (blue) are scattered more effectively than longer wavelengths (red) by atmospheric gases (Rayleigh scattering). - The path length of sunlight through the atmosphere affects which colours are predominantly seen.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/exam.pscnotes.com\/mcq\/the-blue-colour-of-the-sky-and-the-reddening-of-the-sun-at-sunrise-and\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The blue colour of the sky and the reddening of the Sun at sunrise and\" \/>\n<meta property=\"og:description\" content=\"The blue colour of the sky and the reddening of the Sun at sunrise and sunset are classic examples of the phenomenon of scattering of light by particles in the atmosphere. When sunlight enters the Earth's atmosphere, it interacts with the gas molecules (mainly Nitrogen and Oxygen) and tiny particles present. This interaction causes the light to be scattered in various directions. This process is called scattering. Rayleigh scattering explains why the sky is blue. It states that the intensity of scattered light is inversely proportional to the fourth power of the wavelength. Shorter wavelengths, like blue and violet light, are scattered much more effectively than longer wavelengths, like red and orange light. When we look at the sky during the day, we see the scattered blue light from all directions. At sunrise and sunset, the sunlight travels a much longer path through the atmosphere to reach our eyes. During this long journey, most of the shorter wavelength blue and green light is scattered away by the atmospheric particles. The longer wavelength light, such as red and orange, which is scattered less, is left to reach our eyes, making the Sun and the sky around it appear reddish or orange. - The colour of the sky and the Sun's colour at sunrise\/sunset are due to the interaction of sunlight with atmospheric particles. - This interaction involves scattering of light. - Shorter wavelengths (blue) are scattered more effectively than longer wavelengths (red) by atmospheric gases (Rayleigh scattering). - The path length of sunlight through the atmosphere affects which colours are predominantly seen.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/the-blue-colour-of-the-sky-and-the-reddening-of-the-sun-at-sunrise-and\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T11:42:22+00:00\" \/>\n<meta name=\"author\" content=\"rawan239\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"rawan239\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"The blue colour of the sky and the reddening of the Sun at sunrise and","description":"The blue colour of the sky and the reddening of the Sun at sunrise and sunset are classic examples of the phenomenon of scattering of light by particles in the atmosphere. 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The longer wavelength light, such as red and orange, which is scattered less, is left to reach our eyes, making the Sun and the sky around it appear reddish or orange. - The colour of the sky and the Sun's colour at sunrise\/sunset are due to the interaction of sunlight with atmospheric particles. - This interaction involves scattering of light. - Shorter wavelengths (blue) are scattered more effectively than longer wavelengths (red) by atmospheric gases (Rayleigh scattering). - The path length of sunlight through the atmosphere affects which colours are predominantly seen.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/exam.pscnotes.com\/mcq\/the-blue-colour-of-the-sky-and-the-reddening-of-the-sun-at-sunrise-and\/","og_locale":"en_US","og_type":"article","og_title":"The blue colour of the sky and the reddening of the Sun at sunrise and","og_description":"The blue colour of the sky and the reddening of the Sun at sunrise and sunset are classic examples of the phenomenon of scattering of light by particles in the atmosphere. 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The longer wavelength light, such as red and orange, which is scattered less, is left to reach our eyes, making the Sun and the sky around it appear reddish or orange. - The colour of the sky and the Sun's colour at sunrise\/sunset are due to the interaction of sunlight with atmospheric particles. - This interaction involves scattering of light. - Shorter wavelengths (blue) are scattered more effectively than longer wavelengths (red) by atmospheric gases (Rayleigh scattering). - The path length of sunlight through the atmosphere affects which colours are predominantly seen.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/the-blue-colour-of-the-sky-and-the-reddening-of-the-sun-at-sunrise-and\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T11:42:22+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/the-blue-colour-of-the-sky-and-the-reddening-of-the-sun-at-sunrise-and\/","url":"https:\/\/exam.pscnotes.com\/mcq\/the-blue-colour-of-the-sky-and-the-reddening-of-the-sun-at-sunrise-and\/","name":"The blue colour of the sky and the reddening of the Sun at sunrise and","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T11:42:22+00:00","dateModified":"2025-06-01T11:42:22+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The blue colour of the sky and the reddening of the Sun at sunrise and sunset are classic examples of the phenomenon of scattering of light by particles in the atmosphere. 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