{"id":40599,"date":"2024-05-02T10:41:37","date_gmt":"2024-05-02T10:41:37","guid":{"rendered":"https:\/\/edukemy.com\/blog\/?p=40599"},"modified":"2024-05-02T10:41:39","modified_gmt":"2024-05-02T10:41:39","slug":"upsc-prelims-topic-wise-questions-physics-modern-physics","status":"publish","type":"post","link":"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/","title":{"rendered":"UPSC Prelims Topic Wise Questions &#8211; Physics &#8211; Modern Physics"},"content":{"rendered":"\n\n\n<p>Discover a curated collection of UPSC Prelims topic-wise questions on Physics, focusing specifically on Modern Physics. This resource provides a comprehensive set of questions covering key concepts such as quantum mechanics, relativity, atomic and nuclear physics, and particle physics. Each question is meticulously designed to help aspirants deepen their understanding and proficiency in Modern Physics topics relevant to the UPSC Preliminary Examination. By engaging with these questions, candidates can enhance their problem-solving skills, critical thinking abilities, and overall exam preparedness. Whether you&#8217;re a novice or a seasoned aspirant, this resource offers a structured approach to mastering Modern Physics concepts and maximizing your chances of success in the UPSC Prelims. Dive into this invaluable resource to refine your knowledge and excel in the Physics segment of the UPSC examination.<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_73 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<label for=\"ez-toc-cssicon-toggle-item-69d2f419e6234\" class=\"ez-toc-cssicon-toggle-label\"><p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-cssicon\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-69d2f419e6234\"  \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q1_Which_one_of_the_following_can_be_used_to_confirm_whether_drinking_water_contains_a_gamma_emitting_isotope_or_not_1995\" title=\"Q1. Which one of the following can be used to confirm whether drinking water contains a gamma emitting isotope or not? (1995)\">Q1. Which one of the following can be used to confirm whether drinking water contains a gamma emitting isotope or not? (1995)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_c\" title=\"Ans. (c)\">Ans. (c)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q2_The_difference_between_a_nuclear_reactor_and_an_atomic_bomb_is_that_1995\" title=\"Q2. The difference between a nuclear reactor and an atomic bomb is that (1995)\">Q2. The difference between a nuclear reactor and an atomic bomb is that (1995)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_b\" title=\"Ans. (b)\">Ans. (b)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q3_The_technique_used_to_transmit_audio_signals_in_television_broadcasts_is_1995\" title=\"Q3. The technique used to transmit audio signals in television broadcasts is (1995)\">Q3. The technique used to transmit audio signals in television broadcasts is (1995)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_b-2\" title=\"Ans. (b)\">Ans. (b)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q4_Which_one_of_the_following_elements_is_essential_for_the_construction_of_nuclear_reactors_1998\" title=\"Q4. Which one of the following elements is essential for the construction of nuclear reactors? (1998)\">Q4. Which one of the following elements is essential for the construction of nuclear reactors? (1998)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_c-2\" title=\"Ans. (c)\">Ans. (c)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q5_Which_one_of_the_following_does_a_TV_remote_control_unit_use_to_operate_a_TV_set_2000\" title=\"Q5. Which one of the following does a TV remote control unit use to operate a TV set? (2000)\">Q5. Which one of the following does a TV remote control unit use to operate a TV set? (2000)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_d\" title=\"Ans. (d)\">Ans. (d)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q6_Consider_the_following_statements_2001\" title=\"Q6. Consider the following statements. (2001)\">Q6. Consider the following statements. (2001)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_a\" title=\"Ans. (a)\">Ans. (a)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q7_Consider_the_following_statements_2002\" title=\"Q7. Consider the following statements. (2002)\">Q7. Consider the following statements. (2002)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_d-2\" title=\"Ans. (d)\">Ans. (d)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q8_Consider_the_following_statements_2005\" title=\"Q8. Consider the following statements (2005)\">Q8. Consider the following statements (2005)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ansb\" title=\"Ans.(b)\">Ans.(b)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q9_In_which_one_of_the_following_areas_did_the_Indira_Gandhi_Centre_for_Atomic_Research_make_significant_progress_in_the_year_2005_2006\" title=\"Q9. In which one of the following areas did the Indira Gandhi Centre for Atomic Research make significant progress in the year 2005? (2006)\">Q9. In which one of the following areas did the Indira Gandhi Centre for Atomic Research make significant progress in the year 2005? (2006)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_a-2\" title=\"Ans (a)\">Ans (a)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q10_What_does_the_term_Dolby_B_or_Dolby_C_printed_on_tape-recorders_and_other_sound_systems_refer_to_2006\" title=\"Q10. What does the term Dolby B or Dolby C printed on tape-recorders and other sound systems refer to? (2006)\">Q10. What does the term Dolby B or Dolby C printed on tape-recorders and other sound systems refer to? (2006)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_c-3\" title=\"Ans. (c)\">Ans. (c)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q11_Assertion_A_Radiowaves_bend_in_a_magnetic_field_Reason_R_Radiowaves_are_electromagnetic_in_nature_2008\" title=\"Q11. Assertion (A) Radiowaves bend in a magnetic field. Reason (R) Radiowaves are electromagnetic in nature. (2008)\">Q11. Assertion (A) Radiowaves bend in a magnetic field. Reason (R) Radiowaves are electromagnetic in nature. (2008)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_d-3\" title=\"Ans. (d)\">Ans. (d)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q12_Which_one_of_the_following_laser_types_is_used_in_a_laser_printer_2008\" title=\"Q12. Which one of the following laser types is used in a \u00a0laser printer? (2008)\">Q12. Which one of the following laser types is used in a \u00a0laser printer? (2008)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_c-4\" title=\"Ans . (c)\">Ans . (c)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q13_Which_one_among_the_following_has_the_highest_energy_2009\" title=\"Q13. Which one among the following has the highest energy? (2009)\">Q13. Which one among the following has the highest energy? (2009)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_a-3\" title=\"Ans. (a)\">Ans. (a)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Q14_Which_one_of_the_following_types_of_waves_are_used_in_a_night_vision_apparatus_2009\" title=\"Q14. Which one of the following types of waves are used in a night vision apparatus? (2009)\">Q14. Which one of the following types of waves are used in a night vision apparatus? (2009)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Ans_c-5\" title=\"Ans. (c)\">Ans. (c)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#In_case_you_still_have_your_doubts_contact_us_on_9811333901\" title=\"In case you still have your doubts, contact us on 9811333901.&nbsp;\">In case you still have your doubts, contact us on 9811333901.&nbsp;<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/edukemy.com\/blog\/upsc-prelims-topic-wise-questions-physics-modern-physics\/#Visit_our_YouTube_Channel_%E2%80%93_here\" title=\"Visit our YouTube Channel &#8211;&nbsp;here\">Visit our YouTube Channel &#8211;&nbsp;here<\/a><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q1_Which_one_of_the_following_can_be_used_to_confirm_whether_drinking_water_contains_a_gamma_emitting_isotope_or_not_1995\"><\/span><strong>Q1. Which one of the following can be used to confirm whether drinking water contains a gamma emitting isotope or not? (1995)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Microscope<\/p>\n\n\n\n<p>(b) Lead plate<\/p>\n\n\n\n<p>(c) Scintillation counter<\/p>\n\n\n\n<p>(d) Spectrophotometer<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_c\"><\/span><strong>Ans. (c)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Option (c), the scintillation counter, is the appropriate tool to confirm the presence of a gamma-emitting isotope in drinking water. This device detects and measures ionizing radiation, particularly gamma rays, by registering the light pulses generated upon interaction with the detector material. It&#8217;s commonly used in radiation detection and environmental monitoring.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q2_The_difference_between_a_nuclear_reactor_and_an_atomic_bomb_is_that_1995\"><\/span><strong>Q2. The difference between a nuclear reactor and an atomic bomb is that (1995)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) no chain reaction takes place in nuclear reactor while in the atomic bomb there is a chain reaction<\/p>\n\n\n\n<p>(b) the chain reaction in nuclear reactor is controlled<\/p>\n\n\n\n<p>(c) the chain reaction in nuclear reactor is not controlled<\/p>\n\n\n\n<p>(d) no chain reaction takes place in atomic bomb while it takes place in nuclear reactor<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_b\"><\/span><strong>Ans. (b)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>The difference between a nuclear reactor and an atomic bomb lies in the control of the chain reaction. In a nuclear reactor, the chain reaction is managed and controlled, allowing for sustained and controlled energy production. On the other hand, in an atomic bomb, the chain reaction is uncontrolled, leading to a rapid and explosive release of energy. Option (b) correctly highlights this distinction, emphasizing the controlled nature of the nuclear reactor&#8217;s chain reaction.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q3_The_technique_used_to_transmit_audio_signals_in_television_broadcasts_is_1995\"><\/span><strong>Q3. The technique used to transmit audio signals in television broadcasts is (1995)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Amplitude Modulation<\/p>\n\n\n\n<p>(b) Frequency Modulation<\/p>\n\n\n\n<p>(c) Pulse Code Modulation<\/p>\n\n\n\n<p>(d) Time Division Multiplexing<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_b-2\"><\/span><strong>Ans. (b)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>The transmission of audio signals in television broadcasts primarily utilizes Frequency Modulation (FM). Unlike Amplitude Modulation (AM), FM keeps the carrier wave&#8217;s amplitude constant while varying its frequency to encode the audio signal. This makes FM less susceptible to amplitude-based noise interference, resulting in clearer audio transmission. Therefore, option (b) is the correct choice.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q4_Which_one_of_the_following_elements_is_essential_for_the_construction_of_nuclear_reactors_1998\"><\/span><strong>Q4. Which one of the following elements is essential for the construction of nuclear reactors? (1998)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Cobalt<\/p>\n\n\n\n<p>(b) Nickel<\/p>\n\n\n\n<p>(c) Zirconium<\/p>\n\n\n\n<p>(d) Tungsten<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_c-2\"><\/span><strong>Ans. (c)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Zirconium is indispensable for the construction of nuclear reactors, particularly in the form of nuclear fuel assemblies. It possesses unique properties such as transparency to neutrons, high-temperature stability, and corrosion resistance, making it an ideal material for containing and moderating nuclear reactions. Thus, option (c) accurately identifies zirconium as an essential element in nuclear reactor construction.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q5_Which_one_of_the_following_does_a_TV_remote_control_unit_use_to_operate_a_TV_set_2000\"><\/span><strong>Q5. Which one of the following does a TV remote control unit use to operate a TV set? (2000)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Light waves<\/p>\n\n\n\n<p>(b) Sound waves<\/p>\n\n\n\n<p>(c) Micro waves<\/p>\n\n\n\n<p>(d) Radio waves<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_d\"><\/span><strong>Ans. (d)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>TV remote control units operate using radio waves to communicate with television sets. Radio waves, characterized by their longer wavelengths and ability to penetrate obstacles, provide an effective means of transmitting control signals between the remote and the TV set. Therefore, option (d) correctly identifies radio waves as the medium used by TV remote control units.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q6_Consider_the_following_statements_2001\"><\/span><strong>Q6. Consider the following statements. (2001)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><em>In a nuclear reactor, self-sustained chain reaction is possible, because<\/em><\/p>\n\n\n\n<p>1. more neutrons are released in each of the fission reactions.<\/p>\n\n\n\n<p>2. the neutrons immediately take part in the fission process.<\/p>\n\n\n\n<p>3. the fast neutrons are slowed down by graphite.<\/p>\n\n\n\n<p>4. every neutron released in the fission reaction initiates further fission.<\/p>\n\n\n\n<p><em>Which of these statements are correct?<\/em><\/p>\n\n\n\n<p>(a) 1, 2 and 3<\/p>\n\n\n\n<p>(b) 1 and 3<\/p>\n\n\n\n<p>(c) 2 and 4<\/p>\n\n\n\n<p>(d) 2, 3 and 4<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_a\"><\/span><strong>Ans. (a)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>The self-sustained chain reaction in a nuclear reactor relies on several factors, including the production and utilization of neutrons. Options (1), (2), and (3) highlight key aspects of this process, such as the release of more neutrons in each fission reaction, the prompt involvement of these neutrons in subsequent fissions, and the role of moderators like graphite in slowing down fast neutrons to sustain the chain reaction. Therefore, option (a) accurately represents the conditions necessary for a self-sustained chain reaction in a nuclear reactor.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q7_Consider_the_following_statements_2002\"><\/span><strong>Q7. Consider the following statements. (2002)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>1. Light of longer wavelength is scattered much than the light of shorter wavelength.<\/p>\n\n\n\n<p>2. The speed of visible light in water is 0.95 times the speed in vacuum.<\/p>\n\n\n\n<p>3. Radio waves are produced by rapidly oscillating electrical current.<\/p>\n\n\n\n<p>4. To detect the over speeding vehicles, police use the Doppler effect of reflected short radio waves.<\/p>\n\n\n\n<p><em>Which of these statements are correct?<\/em><\/p>\n\n\n\n<p>(a) 1 and 2<\/p>\n\n\n\n<p>(b) 1 and 3<\/p>\n\n\n\n<p>(c) 2 and 4<\/p>\n\n\n\n<p>(d) 3 and 4<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_d-2\"><\/span><strong>Ans. (d)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Statements (3) and (4) provide accurate insights into the behavior of light and radio waves. Radio waves are indeed generated by rapidly oscillating electrical currents, and the Doppler effect of reflected short radio waves is utilized by police radar to detect over-speeding vehicles. Therefore, option (d) correctly identifies these statements as accurate descriptions of light and radio wave phenomena.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q8_Consider_the_following_statements_2005\"><\/span><strong>Q8. Consider the following statements (2005)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>1. A geo-stationary satellite is at an approximate height of 1000 km.<\/p>\n\n\n\n<p>2. FM transmission of music is a very good quality because the atmospheric or man made noises, which are generally frequency variations can do little harm.<\/p>\n\n\n\n<p><em>Which of the statements given above is\/are correct?<\/em><\/p>\n\n\n\n<p>(a) Only 1<\/p>\n\n\n\n<p>(b) Only 2<\/p>\n\n\n\n<p>(c) Both 1 and 2<\/p>\n\n\n\n<p>(d) Neither 1 nor 2<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ansb\"><\/span><strong>Ans.(b)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Statement (2) is accurate. FM transmission of music delivers high-quality sound due to its immunity to atmospheric or man-made noise, which often manifests as frequency variations. Unlike AM transmission, FM transmission is resilient against such noise, as noise typically involves amplitude variations caused by factors like atmospheric conditions or industrial interference. Statement (1), however, is erroneous. A geostationary satellite orbits Earth at an approximate altitude of 3600 km, revolving from West to East in a plane aligned with the equator. These satellites play a crucial role in reflecting TV signals and facilitating the transmission of TV programs across different parts of the globe.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q9_In_which_one_of_the_following_areas_did_the_Indira_Gandhi_Centre_for_Atomic_Research_make_significant_progress_in_the_year_2005_2006\"><\/span><strong>Q9. In which one of the following areas did the Indira Gandhi Centre for Atomic Research make significant progress in the year 2005? (2006)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Reprocessing the uranium-plutonium mixed carbide fuel of the Fast Breeder Test Reactor<\/p>\n\n\n\n<p>(b) New applications of radioisotopes in metallurgy<\/p>\n\n\n\n<p>(c) A new technology for production of heavy water<\/p>\n\n\n\n<p>(d) A new technology for high level nuclear waste management<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_a-2\"><\/span><strong>Ans (a)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>In 2005, significant strides were made by the Indira Gandhi Centre for Atomic Research in reprocessing the uranium-plutonium mixed carbide fuel of the Fast Breeder Test Reactor. Despite fast neutrons&#8217; limited efficacy in causing fission, they readily interact with a uranium isotope (U<sub>238<\/sub>), converting it into Pu<sub>239<\/sub>. This plutonium isotope can be reprocessed for use as additional reactor fuel or in the production of nuclear weaponry. The reactor, known as a Fast Breeder Nuclear Reactor, represents a key advancement in nuclear technology.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q10_What_does_the_term_Dolby_B_or_Dolby_C_printed_on_tape-recorders_and_other_sound_systems_refer_to_2006\"><\/span><strong>Q10. What does the term Dolby B or Dolby C printed on tape-recorders and other sound systems refer to? (2006)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Frequency modulated system<\/p>\n\n\n\n<p>(b) Amplitude modulated system<\/p>\n\n\n\n<p>(c) Noise reduction circuit<\/p>\n\n\n\n<p>(d) Both DC and AC power can be used<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_c-3\"><\/span><strong>Ans. (c)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>The term &#8220;Dolby B&#8221; or &#8220;Dolby C&#8221; found on tape recorders and similar sound systems denotes a noise reduction circuit developed by Dolby Laboratories for analog magnetic tape recording systems. Dolby A and Dolby SR were tailored for professional applications, while Dolby B, C, and S were designed for consumer use.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q11_Assertion_A_Radiowaves_bend_in_a_magnetic_field_Reason_R_Radiowaves_are_electromagnetic_in_nature_2008\"><\/span><strong>Q11. Assertion (A) Radiowaves bend in a magnetic field. Reason (R) Radiowaves are electromagnetic in nature. (2008)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>Codes<\/strong><\/p>\n\n\n\n<p>(a) Both A and R are true and R is the correct explanation of A.<\/p>\n\n\n\n<p>(b) Both A and R are true but R is not the correct explanation of A.<\/p>\n\n\n\n<p>(c) A is true but R is false.<\/p>\n\n\n\n<p>(d) A is false but R is true.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_d-3\"><\/span><strong>Ans. (d)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Assertion (A) is false, but the reason (R) is accurate. Radio waves are indeed electromagnetic in nature. They lack an inherent charge and therefore do not interact with charged particles like electrons. Instead, radio waves consist of oscillating electric and magnetic fields perpendicular to their direction of propagation. Consequently, radio waves do not bend in a magnetic field.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q12_Which_one_of_the_following_laser_types_is_used_in_a_laser_printer_2008\"><\/span><strong>Q12. Which one of the following laser types is used in a \u00a0laser printer? (2008)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Dye laser<\/p>\n\n\n\n<p>(b) Gas laser<\/p>\n\n\n\n<p>(c) Semiconductor laser<\/p>\n\n\n\n<p>(d) Excimer laser<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_c-4\"><\/span><strong>Ans . (c)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Semiconductor lasers, also known as diode lasers, are employed in laser printers due to their ability to be incorporated into larger arrays functioning as writing sources. Unlike solid-state lasers, semiconductor lasers are electronic devices characterized by their compact size and low power consumption. Today, semiconductor lasers, leveraging materials akin to those in transistors, integrated circuits, and light-emitting diodes, dominate the laser market.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q13_Which_one_among_the_following_has_the_highest_energy_2009\"><\/span><strong>Q13. Which one among the following has the highest energy?<\/strong> <strong>(2009)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Blue light<\/p>\n\n\n\n<p>(b) Green light<\/p>\n\n\n\n<p>(c) Red light<\/p>\n\n\n\n<p>(d) Yellow light<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_a-3\"><\/span><strong>Ans. (a)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Blue light boasts the highest energy among the options provided. According to the equation E = hv = hc\/\u03bb, where E represents energy, h is Planck&#8217;s constant, v denotes frequency, c stands for the speed of light, and \u03bb signifies wavelength, lower wavelengths correspond to higher energy levels. Therefore, blue light, with its shorter wavelength, exhibits the highest energy.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Q14_Which_one_of_the_following_types_of_waves_are_used_in_a_night_vision_apparatus_2009\"><\/span><strong>Q14. Which one of the following types of waves are used in a night vision apparatus? (2009)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>(a) Radiowaves<\/p>\n\n\n\n<p>(b) Microwaves<\/p>\n\n\n\n<p>(c) Infrared waves<\/p>\n\n\n\n<p>(d) None of these<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ans_c-5\"><\/span><strong>Ans. (c)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Infrared waves are utilized in night vision apparatuses owing to their capacity to emit heat. Night vision technology enables vision in low-light conditions through a combination of sufficient spectral and intensity ranges. Night Vision Devices (NVDs), containing infrared image intensifier tubes within robust casings, are commonly employed by military personnel. Increasingly, civilian applications of night vision technology, including filming, photography, nocturnal observation, marine navigation, and security, are becoming more prevalent. Some vehicle manufacturers integrate portable night vision cameras into their automobiles for added safety and visibility.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><a href=\"https:\/\/edukemy.com\/upsc\/upsc-essay?utm_source=Blog&amp;utm_medium=Banner&amp;utm_campaign=Essay\" target=\"_blank\" rel=\"noreferrer noopener\"><img fetchpriority=\"high\" decoding=\"async\" src=\"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2024\/06\/UPSC-Essay-Course-1280\u00d7300-1-3.svg\" alt=\"\" class=\"wp-image-42688\" width=\"781\" height=\"182\"\/><\/a><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"In_case_you_still_have_your_doubts_contact_us_on_9811333901\"><\/span><strong>In case you still have your doubts, contact us on 9811333901.<\/strong>&nbsp;<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>For UPSC Prelims Resources,&nbsp;<a href=\"https:\/\/edukemy.com\/upsc-cse-prelims-resource-centre\" target=\"_blank\" rel=\"noreferrer noopener\">Click here<\/a><\/p>\n\n\n\n<p>For Daily Updates and Study Material:<\/p>\n\n\n\n<p>Join our Telegram Channel &#8211;&nbsp;<a href=\"https:\/\/t.me\/WithEdukemy4IAS\" target=\"_blank\" rel=\"noreferrer noopener\">Edukemy for IAS<\/a><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>1. Learn through Videos &#8211;&nbsp;<a href=\"https:\/\/bit.ly\/3vOD8sU\" target=\"_blank\" rel=\"noreferrer noopener\">here<\/a><\/li><li>2. Be Exam Ready by Practicing Daily MCQs &#8211;&nbsp;<a href=\"https:\/\/bit.ly\/3Q9z2nF\" target=\"_blank\" rel=\"noreferrer noopener\">here<\/a><\/li><li>3. Daily Newsletter &#8211; Get all your Current Affairs Covered &#8211;&nbsp;<a href=\"https:\/\/bit.ly\/3bE2y5J\" target=\"_blank\" rel=\"noreferrer noopener\">here<\/a><\/li><li>4. Mains Answer Writing Practice &#8211;&nbsp;<a href=\"https:\/\/bit.ly\/3mZuVxl\" target=\"_blank\" rel=\"noreferrer noopener\">here<\/a><\/li><\/ul>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Visit_our_YouTube_Channel_%E2%80%93_here\"><\/span>Visit our YouTube Channel &#8211;&nbsp;<a href=\"https:\/\/www.youtube.com\/@EduKemyforIAS\">here<\/a><span class=\"ez-toc-section-end\"><\/span><\/h4>\n","protected":false},"excerpt":{"rendered":"<p>Discover a curated collection of UPSC Prelims topic-wise questions on Physics, focusing specifically on Modern Physics.<\/p>\n","protected":false},"author":21,"featured_media":40600,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_eb_attr":"","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"categories":[3078],"tags":[250,232,231,179,140],"class_list":["post-40599","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-upsc-prelims-topic-wise-question","tag-physics","tag-upsc","tag-upsc-prelims","tag-upsc-prelims-strategy","tag-upsc_preparation_strategy"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/posts\/40599","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/users\/21"}],"replies":[{"embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/comments?post=40599"}],"version-history":[{"count":2,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/posts\/40599\/revisions"}],"predecessor-version":[{"id":40602,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/posts\/40599\/revisions\/40602"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/media\/40600"}],"wp:attachment":[{"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/media?parent=40599"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/categories?post=40599"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/tags?post=40599"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}