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Reading Comprehension Part - 5 (in Hindi)
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This lesson presents the important questions of reading comprehension for NTA UGC NET.

Sandeep
Co-founder of BSI Academy and running YouTube channel. 5 years of teaching experience. Qualified in UGC NET & CSIR in Computer Science as JR

U
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lord northbrook ke samay hua tha deposition of gaekward of baroda 1875
  1. NTA UGC NET Paper - 1


  2. About Me Sandeep M.Tech (IT) from IIIT CSIR (Engineering Science) as JRF UGC NET (JRF) Computer Science & Applications Worked as Software Engineer & Research Scientist


  3. Reading Comprehension


  4. Part 5


  5. unacademy 09 45:14PM Follow me on the Unacademy Learning App 127.1k Sandeep Singh Educator since May 2018 Co-founder of BSI Academy 5 years of teaching Qualified in UGC NET in Computer Science and its .Get updates about new courses Watch all my lessons Download slides and watch offline Application as JRF&lecturer 147k 0 34 Follow All courses Q Sandeep Singh HINDI Programming in C&C (Hindi) Concepts of Objects Oriented Programming CBSE UGC NET (6 rating Sandeep Singh


  6. Milankovitch proposed in the early twentieth century that the ice ages were caused by variations in the Earth's orbit around the Sun. For sometime, this theory was considered untestable, largely because there was no sufficiently precise chronology of the ice ages with which the orbital variations could be matched. To establish such a chronology it is necessary to determine the relative amounts of land ice that existed at various times in the Earth's past. A recent discovery makes such a determination possible: relative land-ice volume for a given period can be deduced from the ratio of two oxygen isotopes, 16 and 18, found in ocean sediments. Almost all the oxygen in water is oxygen 16, but a few molecules out of every thousand incorporate the heavier isotope 18. When an ice age begins, the continental ice sheets grow, steadily reducing the amount of water evaporated from the ocean that will eventually return to it. Because heavier isotopes tend to be left behind when water evaporates from the ocean surfaces, the remaining ocean water becomes progressively enriched in oxygen 18.


  7. The degree of enrichment can be determined by analyzing ocean sediments of the period, because these sediments are composed of calcium carbonate shells of marine organisms shells that were constructed with oxygen atoms drawn from the surrounding ocean. The higher the ratio of oxygen 18 to oxygen 16 in a sedimentary specimen the more land ice there was when the sediment was laid down As an indicator of shifts in the Earth's climate, the isotope record has two advantages. First, it is a global record: there is remarkably little variation in isotope ratios in sedimentary specimens taken from different continental locations.


  8. Second, it is a more continuous record than that taken from rocks on land. Because of these advantages, sedimentary evidence can be dated with sufficient accuracy by radiometric methods to establish a precise chronology of the ice ages. The dated isotope record shows that the fluctuations in global ice volume over the past several hundred thousand years have a pattern: an ice age occurs roughly once every 100000 years. These data have established a strong connection between variations in the Earth's orbit and the periodicity of the ice ages.


  9. However, it is important to note that other factors, such as volcanic particulates or variations in the amount of sunlight received by the Earth, could potentially h felanhonvichthoryis tha testable. Changes in the Earth's orbit can be calculated and dated by applying Newton's laws of gravity to progressively earlier configurations of the bodies in the solar system. Yetthe lack of information about other possible factors affecting global climate does not make them unimportant.


  10. Q. 1 Consider the following statements regarding the ratios of oxygen isotopes in ocean sediments 1. They are less reliable than the evidence from rocks on land in determining the volume of land ice. 2. They can be used to deduce the relative volume of land ice that was present when the sediment was laid down. 3. They indicate that sediments found during an ice age contain more calcium carbonate than sediments formed at other times 4. They can be used to determine atmospheric conditions at various times in the past. Which of the above statement (s) are incorrect? [A] 2 and 3 [C] 2, 3 and 4 [B] 1 and 4 [D] 1, 3 and 4


  11. Q. 2 This question consists of an Assertion (A) and a Reason (R). Indicate your answer by selecting the correct alternative Assertion (A): Rain and snow formed from evaporated ocean water has the same isotopic ratio as ocean water. Reason (R): Heavier isotopes tend to be left behind when water evaporates from the ocean surfaces [A] Both A and R are right and R is the correct explanation for A [B] Both A and R are right but R is not the correct explanation for A [C] A is right but R is wrong [D] A is wrong but R is right


  12. Q. 3 Consider the following statements regarding the ice ages. 1. Ice ages have lasted about 10000 years for at least the last several hundred thousand years 2. Ice ages have occurred about every 100000 years for at least the last several hundred thousand years 3. The last ice age occurred about 25000 years ago. Which of the above statements are true, as per the passage? [A] Only 1 [B] 2 and 3 [C] Only 2 [D] All of these


  13. Q. 4 Which one of the following can be inferred about calcium carbonate shells from the passage? [A] They are not as susceptible to deterioration as rocks B] They reflect the isotopic composition of water at the time the shells were formed [C] They are less common in sediments formed during an ice age [D] They are found only in areas that were once covered by land ice


  14. Q. 5 Consider the following statements regarding the properties of ocean sediments 1. They correspond with the isotope ratios of ice volume taken from rocks on land. 2. They provide data that can be used to substantiate records concerning variations in the amount of sunlight received by the Earth. 3. They confirm the record of ice volume initially established by analyzing variations in volcanic emissions 4. They show little variation in isotope ratios. When samples are taken from different continental locations. Which of the above statements are correct, as per the passage? IA] Only 4 [B] 2, 3 and 4 [C] 1 and 2 [D] 1, 2 and 3


  15. Q. 5 Consider the following statements regarding the properties of ocean sediments 1. They correspond with the isotope ratios of ice volume taken from rocks on land. 2. They provide data that can be used to substantiate records concerning variations in the amount of sunlight received by the Earth. 3. They confirm the record of ice volume initially established by analyzing variations in volcanic emissions 4. They show little variation in isotope ratios. When samples are taken from different continental locations. Which of the above statements are correct, as per the passage? IA] Only 4 [B] 2, 3 and 4 [C] 1 and 2 [D] 1, 2 and 3


  16. Thank You