4 mins 12 secs to all correct but the last question.
SajjadAhmad, I feel the OA to Q7 should be D. Please look into it.
Summary: The passage begins with talking about the importance of CO2 in the atmosphere and goes on to warn about the probable negative effects of growing CO2 over the last hundred years. It then details how mathematical models help predict the average temperature rise with growing CO2 and further adds that one of these models assumes constant humidity. Also, towards the end, a positive loop is described where rising temperature leads to the melting of polar ice caps and loss of reflectivity of earth leading to even higher heat capture and more temperature.
Need to focus on the main point of the passage and not on the details used to convey it.1. The primary purpose of the passage is to(A) warn of the dangers of continued burning of fossil fuels
Again, fossil fuels is indirectly the cause of the direct material being discussed i.e CO2(B) discuss the significance of increasing the amount of carbon dioxide in the atmosphere
Perfect - this is the heart of the content.(C) explain how a constant temperature is maintained on the Earth’s surface
This is just a detail used to show the importance of CO2 in the first paragraph(D) describe the ways in which various atmospheric and climatic conditions contribute to the Earth’s weather
Earth's weather is out of context and too broad we are only looking to talk about CO2 and average temperature.(E) demonstrate the usefulness of mathematical models in predicting long-range climatic change
Again, not the main point but a means to an end.Direct detail question from the passage2. According to the passage, the greatest part of the solar energy that reaches the Earth is(A) concentrated in the infrared spectrum
(B) concentrated at visible wavelengths
Perfect - mentioned in the passage(C) absorbed by carbon dioxide molecules
(D) absorbed by atmospheric water vapor
(E) reflected back to space by snow and ice
EXCEPT type - so we are looking for the one option that does not fit or is incorrect3. According to the passage, atmospheric carbon dioxide performs all of the following functions EXCEPT:(A) absorbing radiation at visible wavelengths
Perfect - it is said to only absorb the infrared wavelength(B) absorbing infrared radiation
Given in the passage(C) absorbing outgoing radiation from the Earth
Mentioned - again infrared only(D) helping to retain heat near the Earth’s surface
Given - this is what the passage talks about!(E) helping to maintain a constant average temperature on the Earth’s surface
This is the end point of CO2 heat capture as per the first paragraphAuthor's tone is to be judged by the key words the author uses and also need to look at the end of each paragraph to search for them in addition to the end of the passage4. Which of the following best describes the author’s attitude toward the increasing amount of carbon dioxide in the atmosphere and its consequences?(A) Incredulous
Not even close!(B) Completely detached
The author does not show to be detached, infact is actively researching and quoting models etc. Wrong.(C) Interested but skeptical
Author is definitely interested but does not show skepticism(D) Angry yet resigned
Laughably incorrect(E) Objective yet concerned
Perfect - objective as the author uses math models to express the content and concern for the probable negative impact of the increase of CO2 on Human lifeDirect application question. QUITE UNIQUE! The passage mentions a drop of 6 deg per km from the surface and that the surface is at a mean of 15 deg5. It can be concluded from information contained in the passage that the average temperature at an altitude of 1 kilometer above the Earth is about(A) 15℃
(B) 9℃
CORRECT(C) 2.5℃
(D) -12℃
(E) -18℃
The author takes quite some time to explain that the model assumes a constant humidity and then goes one step forward to explain what this assumption entails - so we need to definitely look out for this in the options.6. It can be inferred from the passage that the construction of the mathematical model mentioned in the passage involved the formulation of which of the following?(A) An assumption that the amount of carbon dioxide added to the atmosphere would in reality steadily increase
Unrelated - the author was talking about twice the amount present curently - so steady increase is wrong - moreover this is the hypothesis of the model and not the assumption(B) An assumption that human activities are the only agencies by which carbon dioxide is added to the atmosphere
Out of scope of the math model(C) Assumptions about the social and political consequences of any curtailment of the use of fossil fuels
Way out of scope of the model(D) Assumptions about the physical conditions that are likely to prevail during the period for which the model was made
Perfect - mentioned in a esoteric way but "physical conditions" can rightly describe a physical concept of humidity. correct answer(E) Assumptions about the differential behavior of carbon dioxide molecules at the various levels of temperature calculated in the model
Never mentionedOA should be D according to me. But currently given as B.Detail question asked from directly mentioned information from the passage7. According to the passage, which of the following is true of the last hundred years?(A) Fossil fuels were burned for the first time.
Again - this has not been mentioned. "For the first time" makes this option incorrect(B) Greater amounts of land were cleared than at any time before.
"Than any time before" is too extreme and not mentioned in the passage(C) The average temperature at the Earth’s surface has become 2℃ cooler.
Opposite of what is mentioned - the average temperature increased(D) The amount of carbon dioxide in the atmosphere has increased measurably.
Perfect - the passage talks about a 15% increase in the atmospheric CO2 - this is definitely a measurable jump(E) The amount of farmland worldwide has doubled.
Out of scope - not mentionedHope this helps.