{"id":90451,"date":"2025-06-01T10:28:51","date_gmt":"2025-06-01T10:28:51","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=90451"},"modified":"2025-06-01T10:28:51","modified_gmt":"2025-06-01T10:28:51","slug":"the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/","title":{"rendered":"The radar used by police to check over-speeding vehicles works on the"},"content":{"rendered":"

The radar used by police to check over-speeding vehicles works on the principle of<\/p>\n

[amp_mcq option1=”Raman effect” option2=”Induction effect” option3=”Doppler effect” option4=”Coulomb effect” correct=”option3″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC CAPF – 2020<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nThe radar used by police to check over-speeding vehicles works on the principle of the Doppler effect.
\n<\/section>\n
\nThe Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. Police radar guns emit radio waves towards a moving vehicle. When these waves reflect off the vehicle, their frequency is shifted. If the vehicle is moving towards the radar, the reflected waves have a higher frequency; if moving away, they have a lower frequency. The radar unit measures this frequency shift and calculates the vehicle’s speed based on the magnitude of the shift.
\n<\/section>\n
\nThe Raman effect involves inelastic scattering of photons. The Induction effect relates to the production of an electromotive force across an electrical conductor in a changing magnetic field. The Coulomb effect describes the electrostatic interaction between charged particles. None of these principles are the basis for how police speed radar operates.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

The radar used by police to check over-speeding vehicles works on the principle of [amp_mcq option1=”Raman effect” option2=”Induction effect” option3=”Doppler effect” option4=”Coulomb effect” correct=”option3″] This question was previously asked in UPSC CAPF – 2020 Download PDFAttempt Online The radar used by police to check over-speeding vehicles works on the principle of the Doppler effect. The … <\/p>\n

Detailed SolutionThe radar used by police to check over-speeding vehicles works on the<\/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":[1085],"tags":[1288,1128,1274],"class_list":["post-90451","post","type-post","status-publish","format-standard","hentry","category-upsc-capf","tag-1288","tag-physics","tag-wave-motion","no-featured-image-padding"],"yoast_head":"\nThe radar used by police to check over-speeding vehicles works on the<\/title>\n<meta name=\"description\" content=\"The radar used by police to check over-speeding vehicles works on the principle of the Doppler effect. The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. Police radar guns emit radio waves towards a moving vehicle. When these waves reflect off the vehicle, their frequency is shifted. If the vehicle is moving towards the radar, the reflected waves have a higher frequency; if moving away, they have a lower frequency. The radar unit measures this frequency shift and calculates the vehicle's speed based on the magnitude of the shift.\" \/>\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-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The radar used by police to check over-speeding vehicles works on the\" \/>\n<meta property=\"og:description\" content=\"The radar used by police to check over-speeding vehicles works on the principle of the Doppler effect. The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. Police radar guns emit radio waves towards a moving vehicle. When these waves reflect off the vehicle, their frequency is shifted. If the vehicle is moving towards the radar, the reflected waves have a higher frequency; if moving away, they have a lower frequency. The radar unit measures this frequency shift and calculates the vehicle's speed based on the magnitude of the shift.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T10:28:51+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=\"1 minute\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"The radar used by police to check over-speeding vehicles works on the","description":"The radar used by police to check over-speeding vehicles works on the principle of the Doppler effect. The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. Police radar guns emit radio waves towards a moving vehicle. When these waves reflect off the vehicle, their frequency is shifted. If the vehicle is moving towards the radar, the reflected waves have a higher frequency; if moving away, they have a lower frequency. The radar unit measures this frequency shift and calculates the vehicle's speed based on the magnitude of the shift.","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-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/","og_locale":"en_US","og_type":"article","og_title":"The radar used by police to check over-speeding vehicles works on the","og_description":"The radar used by police to check over-speeding vehicles works on the principle of the Doppler effect. The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. Police radar guns emit radio waves towards a moving vehicle. When these waves reflect off the vehicle, their frequency is shifted. If the vehicle is moving towards the radar, the reflected waves have a higher frequency; if moving away, they have a lower frequency. The radar unit measures this frequency shift and calculates the vehicle's speed based on the magnitude of the shift.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T10:28:51+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/","url":"https:\/\/exam.pscnotes.com\/mcq\/the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/","name":"The radar used by police to check over-speeding vehicles works on the","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T10:28:51+00:00","dateModified":"2025-06-01T10:28:51+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The radar used by police to check over-speeding vehicles works on the principle of the Doppler effect. The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. Police radar guns emit radio waves towards a moving vehicle. When these waves reflect off the vehicle, their frequency is shifted. If the vehicle is moving towards the radar, the reflected waves have a higher frequency; if moving away, they have a lower frequency. The radar unit measures this frequency shift and calculates the vehicle's speed based on the magnitude of the shift.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/the-radar-used-by-police-to-check-over-speeding-vehicles-works-on-the\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CAPF","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-capf\/"},{"@type":"ListItem","position":3,"name":"The radar used by police to check over-speeding vehicles works on the"}]},{"@type":"WebSite","@id":"https:\/\/exam.pscnotes.com\/mcq\/#website","url":"https:\/\/exam.pscnotes.com\/mcq\/","name":"MCQ and Quiz for Exams","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/exam.pscnotes.com\/mcq\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209","name":"rawan239","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","caption":"rawan239"},"sameAs":["https:\/\/exam.pscnotes.com"],"url":"https:\/\/exam.pscnotes.com\/mcq\/author\/rawan239\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/90451","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/comments?post=90451"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/90451\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=90451"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=90451"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=90451"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}