During the twelfth century, the Indian author Bhaskara published a

Question

During the twelfth century, the Indian author Bhaskara published a drawing of a wheel with an odd number of sealed containers of mercury around its outer rim. According to the designer, as the wheel spun the cylinders of mercury would spin with it. Each time a cylinder reached the top of the wheel, gravity would pull the mercury from one side of the container to the other and exert a continuous downward force on the wheel, thus enabling it to turn perpetually without external energy. This scheme marked the first documented attempt to design a perpetual motion machine. Like the study of alchemy, the notion of perpetual motion machines has enticed inventors with the impossible for centuries; since Bhaskara’s proposal, countless designers, through either fraud or wishful thinking, claimed to have devised similar contraptions.

By definition, a perpetual motion machine is a device that can operate continuously and supply useful work with no external power source. While processes in nature such as the carbon or hydrologic cycles appear to be perpetual, they are in fact driven by the energy of the sun in the same way that a hydroelectric power plant is driven by the external power of a waterfall. Perpetual motion machines, on the other hand, are designed to harness the potential energy of gravity, buoyancy, or other physical forces in a perfectly efficient manner that essentially recycles energy.

The science that studies the behavior and rules of energy is thermodynamics. In terms of thermodynamics, there are two types of perpetual motion machines. The first is a machine that provides more energy than it requires, which violates the first law of thermodynamics: energy can neither be created nor destroyed. In the case of Bhaskara’s design, the second law of thermodynamics is violated. The second law asserts that in all energy transfers in a closed system, the potential energy after the transfer will be less than the initial potential energy, with the difference lost to dissipative forces such as drag or friction in the form of heat. Each time the mercury in Bhaskara’s wheel strikes the side of the containers, the impact generates heat, which is dissipated into the air and thus lost from the system. Because of this, 100 percent efficiency cannot be achieved and the machine will eventually come to rest.    1 
 1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics
B. show why the overbalanced wheel cannot be made to do usable work
C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine
D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model
E. reject a design for a perpetual motion machine and propose a working alternative

2 
 2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.
B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.
C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.
D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.
E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.

3 
 3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures
B. illustrate how only sunlight can successfully power perpetual motion cycles
C. elaborate on the definition of perpetual motion machines through apparent examples
D. argue that hydroelectric power plants are not, in fact, perpetual motion machines
E. demonstrate that perpetual motion machines are not designed using solar energy

4 
 4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel?
B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel?
C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy?
D. How might a machine violating the first law of thermodynamics be designed?
E. What is the purpose of the science of thermodynamics?

Archit3110 · Answer

1. C
2. B
3. D
4. D

1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics  ; irrelevant 
 B. show why the overbalanced wheel cannot be made to do usable work  irrelevant 
 C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine  para 1 states
or centuries; since Bhaskara’s proposal, countless designers, through either fraud or wishful thinking, claimed to have devised similar contraptions
 D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model  While processes in nature such as the carbon or hydrologic cycles appear to be perpetual, they are in fact driven by the energy of the sun
 E. reject a design for a perpetual motion machine and propose a working alternative  irrelevant

2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.  not discussed 
 B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.  correct as it violated 2nd law of thermodynamics
 C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.  it did not, infact others tried to copy it 
 D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model  not discussed.
 E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.  irrelevant

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures  not given in any para
 B. illustrate how only sunlight can successfully power perpetual motion cycles  sunlight is not causing perpetual motion
 C. elaborate on the definition of perpetual motion machines through apparent examples  no examples are cited
 D. argue that hydroelectric power plants are not, in fact, perpetual motion machines  correct its related to carbon or hydrologic cycles appear to be perpetual, they are in fact driven by the energy of the sun in the same way that a hydroelectric power plant is driven by the external power of a waterfall.
 E. demonstrate that perpetual motion machines are not designed using solar energy  irrelevant

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel?  impact generates heat, which is dissipated into the air and thus lost from the system
 B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel?  2nd law given
 C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy?  
Each time the mercury in Bhaskara’s wheel strikes the side of the containers, the impact generates heat, which is dissipated into the air and thus lost from the system. Because of this, 100 percent efficiency cannot be achieved and the machine will eventually come to rest.
 D. How might a machine violating the first law of thermodynamics be designed? not disccused 
 E. What is the purpose of the science of thermodynamics?  The science that studies the behavior and rules of energy is thermodynamics.

avinashiitp · Answer

Answer for the passage, 1-D, 2-D, 3-C, 4-A

shivamburma · Answer

1-C
2-B
3-D
4-E
1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics -  nowhere mentioned did not possess proper knowledge 
B. show why the overbalanced wheel cannot be made to do usable work -  NOt mentioned usable or whatever work  
C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine -  i will say okish choice 
D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model -  perpertual cycle not possible in nature  
E. reject a design for a perpetual motion machine and propose a working alternative -  not rejected design

2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel. -  not mentioned bhaskara rejected anything  
B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles. -  can be inferred as it violates 2nd law  
C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed -  not mentioned anywhere . 
D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model. -  not mentioned  
E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines. -  Nopee

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures -  not refute , actually support that naturally pmc not possible  
B. illustrate how only sunlight can successfully power perpetual motion cycles -  nope 
C. elaborate on the definition of perpetual motion machines through apparent examples -  not elaborating but explaining just teh opposite  
D. argue that hydroelectric power plants are not, in fact, perpetual motion machines -  yup , While processes in nature such as the carbon or hydrologic cycles appear to be perpetual, they are in fact driven by the energy of the sun in the same way that a hydroelectric power plant is driven by the external power of a waterfall. 
E. demonstrate that perpetual motion machines are not designed using solar energy -  nopee

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel? -  dissipative force , heat 
B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel? -  2nd law 
C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy? -  because dissipating heat 
D. How might a machine violating the first law of thermodynamics be designed? -  mentioned exactly 
E. What is the purpose of the science of thermodynamics? -  i think this is okish

zyt · Answer

1. The primary purpose of the passage is to:

A.  illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics   
 Only Bhaskara's design has been described, other designer's only fraud or wishful thinking.

B . show why the overbalanced wheel cannot be made to do usable work   
 No, this is not the purpose of the passage

C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine
CORRECT, the first para presents on example, second gives similar example in nature and third paragraph explains that scientist have failed in the pursuit

D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model
Even the so called perpetual machines in nature are powered by sun or external power of waterfall. Not possible to build a working model by scientist or possible in nature

E. reject a design for a perpetual motion machine and propose a working alternative
No working alternative was proposed

2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel. 
 Bhaskara did not reject any law

B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.
CORRECT: this was Bhaskara's goal

C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed. 
 other inventors designed fraudulant machiens not Bhaskara

D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.
Bhaskara had produced a working model of the over balanced wheel

E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.
No, infact he wanted to demonstrate a perpetual motion machine

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures
No the aim of the second para is to show that perpetual energy is recyclable.

B. illustrate how only sunlight can successfully power perpetual motion cycles
false , even hydroelectric and gravity are forces which could potentially power perpetual motion cycles

C. elaborate on the definition of perpetual motion machines through apparent examples
CORRECT, the para begins with definition and goes on to give examples

D. argue that hydroelectric power plants are not, in fact, perpetual motion machines
False, it's not limited to discussion of hydroelectric power

E. demonstrate that perpetual motion machines are not designed using solar energy
False, solar energy can be used to design motion machine

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel? 
dissipative forces such as drag or friction in the form of heat is described in the passage

B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel? 
In the case of Bhaskara’s design, the second law of thermodynamics is violated.

C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy? 
 Each time the mercury in Bhaskara’s wheel strikes the side of the containers, the impact generates heat, which is dissipated into the air and thus lost from the system. Because of this, 100 percent efficiency cannot be achieved and the machine will eventually come to rest id stated in the passage

D. How might a machine violating the first law of thermodynamics be designed? 
 CORRECT ANSWER
Only the first law is mentioned but no machine design described.

E. What is the purpose of the science of thermodynamics?
The science that studies the behavior and rules of energy is thermodynamics is the first line of the passage.

PAB2019 · Answer

1. The primary purpose of the passage is to:
A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics
 The passage is not about any physics who do not possesses the proper knowledge of the laws

B. show why the overbalanced wheel cannot be made to do usable work
 the passage does not talk about doing usable work

C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine
first paragraph describes a theoritically perpetual motion machine design, then says how often later attempt to design such systems where failures. 
then the second paragraph describes what a perpetual motion machine is and show how some system where mistakenly taken as perpetual in motion, 
then the last paragraph brings a view on such systems from the thermodynamic point of view, then conclude that the initial system describe fails to follow the laws necessary to conclude that a system is perpetual in motion

D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model
 The passage showed that the perpetual cycles in nature are not actually perpetual

E. reject a design for a perpetual motion machine and propose a working alternative
 The passage does not reject any design nor does it propose any alternative

2. It can be inferred from the passage that:
A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.
 There is not intention from Bhaskara to reject the thermodynamics laws in the passage

B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles. 
 There is no clue about Bhaskara's introduction of the 100 percent efficiency in the design of his model of wheel

C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.
 Bhaskara's design violate the thermodynamics laws of perpetual movement

D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.
 Bhaskara has just produced a drawing without a further analysis of it, there is no clue of him thinking that the model will work

E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.
 Bhaskara is not trying to demonstrate the impossibility of perpetual motion machines

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:
A. refute the notion that perpetual motion is only possible in technological ventures
 This answer is out of scope here when talking of technological ventures

B. illustrate how only sunlight can successfully power perpetual motion cycles
 The paragraph talks about the energy of Sun not about the sunlight

C. elaborate on the definition of perpetual motion machines through apparent examples
 The paragraph does not give examples of perpetual motion machines but instead gives counter examples

D. argue that hydroelectric power plants are not, in fact, perpetual motion machines 
 The paragraph clearly says how the carbon cycle or a hydrologic cycle falsely appear to be be perpetual

E. demonstrate that perpetual motion machines are not designed using solar energy
 The paragraph is not primarily concerned by the design of the perpetual motion machines working with solar energy

4. The third paragraph supplies information for answering all of the following questions EXCEPT:
A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel?
 at the end of the paragraph it is clearly stated that the heat generated in the Bhaskara's design dissipates into the air

B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel?
 its clearly stated in the paragraph how the two laws of thermodynamic are broken

C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy?
 in the last sentence of the the third paragraph it is stated clearly how the Bhaskar's design fails to achieve totally efficient recycling of energy because of the heat generated by the heat in that model

D. How might a machine violating the first law of thermodynamics be designed? 
 The passage does not precise how a machine violating the first law of thermodynamics must be designed

E. What is the purpose of the science of thermodynamics?
 The purpose (definition) of thermodynamics is given at the beginning of the paragraph

pintukr · Answer

Para 1 : Bhaskara's proposed design of perpetual motion machine. Attempts by other designers, too.
Para 2 : Working principle behind perpetual operating machine
Para 3 : Inherent flaw ie, rejection of laws of thermodynamics by the perceived natural / artificial perpetual motion machines

Overall : While the proposed design claims that perpetual motion machine is possible, there is an inherent violation of the thermodynamics laws in such designs.

1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics
 Scientists' knowledge levels not highlighted 
B. show why the overbalanced wheel cannot be made to do usable work
 Wheel's capability to produce work is NOT the focus, rather ascertaining whether the perpetual motion machine will work in practice  
C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine
 Pursuit through proposed design , along with the inherent violation of thermodynamics laws has been..CORRECT answer discussed 
D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model
 Passage rejects both the natural and artificial design claims 
E. reject a design for a perpetual motion machine and propose a working alternative
 No working alternative has been proposed in the passage

2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.
 Only violation to the 2nd law, not the 1st law 
B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.
 Only with the 100 percent efficiency as the underlying principle, Bhaskara's design of perpetual motion machine will work in actuals...CORRECT answer 
C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.
 No mention of scientific fraud in the passage 
D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.
 Bhaskara's belief can not be ascertained through the passage 
E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.
 Exactly oppsite ie, the 'possibility' of a perpetual motion machine was demonstated was Bhaskara

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures
 refutation of both natural as well as technological designs 
B. illustrate how only sunlight can successfully power perpetual motion cycles
 no such claims about the potential of sunlight 
C. elaborate on the definition of perpetual motion machines through apparent examples
 cycles have been explained to explain the working of perpetual motion machines,..CORRECT answer 
D. argue that hydroelectric power plants are not, in fact, perpetual motion machines
 option too restricted in the scope..no mention of carbon cycle for arguing that hydroelectric power plants are not, in fact, perpetual motion machines 
E. demonstrate that perpetual motion machines are not designed using solar energy
 discussion of hydrologic cycle unrelated to solar energy

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel?
 can be answered ie, drag or friction in the form of heat 
B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel?
 can be answered ie, 2nd law 
C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy?
 can be answered ie, through non consideration of heat dissipation as the loss of potential energy , and thus loss of potential energy in form of heat 
D. How might a machine violating the first law of thermodynamics be designed?
 design of machine violating first law NOT included/proposed in the 3rd paragraph,,CORRECT answer 
E. What is the purpose of the science of thermodynamics?
 can be answered ie, to study the behavior and rules of energy

wadhwakaran · Answer

Broad Idea: Drawing of a wheel with sealed containers filled with mercury to demonstrate Perpetual Motion Machine

P1 How the new wheel would work as PMM without external energy. Since Bhaskara's endeavor, other designers claimed to have devise similar

P2 Discusses about natural processes thought to be PMM but actually are not.

P3 Bhaskara's design violates the second law of thermodynamics and how the cylinder will eventually come to rest.

1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics  Incorrect since the passage details about the design of Bhaskara only. So early scientists is problematic.

B. show why the overbalanced wheel cannot be made to do usable work  Nowhere discussed in the passage.

C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine  True as is mentioned in the first paragraph.

D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model
Even the so called perpetual machines in nature are powered by sun or external power of waterfall. Not possible to build a working model by scientist or possible in nature

E. reject a design for a perpetual motion machine and propose a working alternative  No working alternative is proposed.

2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.  Nowhere mentioned that Bhaskara rejected the validity of LoT. 
B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.
C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.  Incorrect as no one knows when the model proposed by Bhaskara was challenged whether centuries had passed or not is not discussed in the passage. 
D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.  No because he actually believed it to work 
E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.  No contrary to the passage.

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures 
B. illustrate how only sunlight can successfully power perpetual motion cycles 
C. elaborate on the definition of perpetual motion machines through apparent examples
D. argue that hydroelectric power plants are not, in fact, perpetual motion machines  Correct as this was the purpose of the 2nd paragraph to correct the notion about the natural processes thought to be PPM 
E. demonstrate that perpetual motion machines are not designed using solar energy

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel?  Answer to this question is HEAT 
B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel?  Answer to this questions is 2nd Law of Thermodynamics 
C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy?  Answer to this question is YES 
D. How might a machine violating the first law of thermodynamics be designed?  Not known. Therefore the correct answer 
E. What is the purpose of the science of thermodynamics?  The purpose of science of thermodynamics is to study the behaviour and rules of energy.

Sam2021 · Answer

1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics - No mention of erroneous designs 
B. show why the overbalanced wheel cannot be made to do usable work -> Yes correct 
C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine -> Writers tone is not dismissive of the inventor’s design
D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model -> Author is not arguing this. 
E. reject a design for a perpetual motion machine and propose a working alternative -> no alternative is proposed

2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel. -> He did not reject the validity. The second law is violated. 
B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles. -> yes
C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed. -> No, it was not a scientific fraud 
D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model. -> can’t infer this
E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines. -> No it’s the opposite.

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures -> no mention of technology
B. illustrate how only sunlight can successfully power perpetual motion cycles-> No, external force is not needed
C. elaborate on the definition of perpetual motion machines through apparent examples-> yes. Para starts with the def of perpetual motion machines and explains it. 
D. argue that hydroelectric power plants are not, in fact, perpetual motion machines -> That’s not the main purpose of discussing carbon and hydrologic cycles
E. demonstrate that perpetual motion machines are not designed using solar energy -> Not at all.

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel? No mention of this
B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel? Yes 
C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy? How part is not answered
D. How might a machine violating the first law of thermodynamics be designed? No answer is provided for this
E. What is the purpose of the science of thermodynamics? That’s not the crux

gloomybison · Answer

First paragraph talks about that Bhaskara designed first perpetual motion machine model. Afterwards many other tried to invent or claimed to invent such machines.

Second paragraph talks about what perpetual motion machine is, how such motions exist in nature, but how these machines differ from the cycles observed in nature according to the forces from which they draw their energy

Third paragraph talks about the laws of thermodynamic and why Bhaskara's design was flawed

1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics
It does tell that designs were somewhat erroneous in the last paragraph. However we adon't know whether scient did not possess knowledge of laws of physics, they may, presumably, not fully be aware of thermodynamic but saying that no "proper knowledge of the laws" is brutal and too extreme

B. show why the overbalanced wheel cannot be made to do usable work
 Correct

C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine
This one is only stated in the first paragraph
"Like the study of alchemy, the notion of perpetual motion machines has enticed inventors with the impossible for centuries; since Bhaskara’s proposal, countless designers, through either fraud or wishful thinking, claimed to have devised similar contraptions"

D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model
We don't know whether they are possible we know that perpetual motion requires no external force and that what apperas to be perpetual in the nature is actually driven by external forces

E. reject a design for a perpetual motion machine and propose a working alternative

Although it states that machines/models invented so far are flawed because of thermodynamic laws, it does nowhere offer an alternative

2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.
We don't whether he rejected these laws, he may not even be aware of such laws. Yes, his design contradicted with thermodynamic laws but he certainly did not reject validity of these phsyic laws

B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.
 Correct 
%100 percent efficiency is one of the design principle of perpetual motion machines according to paragraph because otherwise it wouldn't be called "perpetual". So yes full efficiency was a fundamental principle but unfortunately not a realistic one beauce of thermodynamic laws

C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.
I would be warmer to this choice if it said "mistake" instead of fraud because we only know that his design was flawed but nothing further.

D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.
We don't whether he brought his model to life. Even if he did he probably would still believed that the machine works because we don't know for how long it will take the machine to eventually come down to rest.

E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.
No not all, if anything he believed that his model would somehow work

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures
Irrelevant

B. illustrate how only sunlight can successfully power perpetual motion cycles
We are not told that sun is the only source. Also we don't whether such a thing appears in nature.

C. elaborate on the definition of perpetual motion machines through apparent examples
 Correct

D. argue that hydroelectric power plants are not, in fact, perpetual motion machines
I think it is viceversa, it says that carbon/hydrologic cycles as perpetual motion as the hydroelectric plants, whch are driven by external forces, making them not so perpetual at all.

E. demonstrate that perpetual motion machines are not designed using solar energy
Irrelevant

4. The third paragraph supplies information for answering all of the following questions EXCEPT :

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel?
"Each time a cylinder reached the top of the wheel, gravity would pull the mercury from one side of the container to the other and exert a continuous downward force on the wheel"

B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel?
"In the case of Bhaskara’s design, the second law of thermodynamics is violated"

C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy?
"Each time the mercury in Bhaskara’s wheel strikes the side of the containers, the impact generates heat, which is dissipated into the air and thus lost from the system. Because of this, 100 percent efficiency cannot be achieved and the machine will eventually come to rest."

D. How might a machine violating the first law of thermodynamics be designed?
 Correct

E. What is the purpose of the science of thermodynamics?
"The science that studies the behavior and rules of energy is thermodynamics."

sanjitscorps18 · Answer

AbRathod · Answer

1. The primary purpose of the passage is to:

Pre thinking - Author explains what is Perpetual motion machine, its goal, and its characteristics. Finally he reaches to the conclusion that these machines do not agree with the laws of thermodynamics and hence these machines cannot reach its goal i.e. perfect efficiency.

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics   Only one design of Bhaskara is shown as an example. Its specific as it covers 3rd para. 
 B. show why the overbalanced wheel cannot be made to do usable work   Too specific , from the third para only. 
 C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine - Correct, matches pre thinking 
 D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model   To produce a working mechanical model is incorrect as it is never mentioned. 
 E. reject a design for a perpetual motion machine and propose a working alternative   No alternative is proposed in the passage.

2. 2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.   No mention of Bhaskara himself rejected / even knowing thermodynamics in the first place.
 B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.  True, "thus enabling it to turn perpetually without external energy" - 1st para , "100 percent efficiency cannot be achieved and the machine will eventually come to rest" - 3rd para.
  C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.   No timeline is stated in the passage to suggest this.
  D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.   - It is the author who might have believed that not Bhaskara.
  E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.
   He had designed it to the demonstrate the possibility of perpetual motion machines.

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures   Nothing about this is mentioned in the first place, other ventures apart from technology are not mentioned.
  B. illustrate how only sunlight can successfully power perpetual motion cycles   Infact its the opposite, gravity is used, however its not why he had discussed.
 C. elaborate on the definition of perpetual motion machines through apparent examples  
D. argue that hydroelectric power plants are not, in fact, perpetual motion machines 2nd Para sheds more light on perpetual motion machines and tells us carbon and hydrlogic cycles are different from perpetual machines in that cycles dont use gravity rather solar energy.
E. demonstrate that perpetual motion machines are not designed using solar energy

happypuppy · Answer

Question 1

1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics
- Wrong - No where 'proper knowledge of the laws of physics' is discussed
B. show why the overbalanced wheel cannot be made to do usable work
- Wrong - Too low in scope
 C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine
- Correct - Best w.r.t POE. the pursuit and ultimate failure is talked in passage 
D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model
- Wrong - Author says opposite. 
E. reject a design for a perpetual motion machine and propose a working alternative
- Wrong - Only one part of passage of rejecting the design.

Question 2

2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.
- Wrong - Rejection is never mentioned.
 B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.
- Correct - Yes!! If Bhaskara didn't include 100% efficiency, his model would have been invalid. 
C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.
- Wrong - No scientific fraud can be inferred.
D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.
- Wrong - Un stated thing in passage.
E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.
- Wrong - Opposite intention as per passage

Question 3
3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures
- Wrong - Can't infer "only possible in technological ventures"
B. illustrate how only sunlight can successfully power perpetual motion cycles
- Wrong - Invalid, no where any other purpose of sunlight discussed.
C. elaborate on the definition of perpetual motion machines through apparent examples
- Wrong - Not the true intension of carbon and hydrologic cycles
 D. argue that hydroelectric power plants are not, in fact, perpetual motion machines
- Correct- Exact intended purpose. 
E. demonstrate that perpetual motion machines are not designed using solar energy
- Wrong - Out of scope

Question 4

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel?
- Wrong - Heat is the answer!
B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel?
- Wrong - 2nd law of thermo.
C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy?
- Wrong - By dissipating heat, mentioned!
 D. How might a machine violating the first law of thermodynamics be designed?
- Correct- Can't be inferred from the passage's 3rd para. 
E. What is the purpose of the science of thermodynamics?
- Wrong - It is given!

Snehaaaaa · Answer

1. The primary purpose of the passage is to:
A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics- The passage does not states that the scientists did not posses a proper knowledge of the the laws of physics
B. show why the overbalanced wheel cannot be made to do usable work- This is not the primary purpose of the passage
 C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine- This is the primary purpose of the passage. This is the correct answer 
D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model- This is not stated in the passage
E. reject a design for a perpetual motion machine and propose a working alternative- No alternative is stated in the passage

2. 2. It can be inferred from the passage that:
A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.- No where in the passage has Bhaskara knowingly rejected the laws of Thermodynamics. 
 B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.- This is implied as per the mechanism explained for perpetual motion machine. This is the correct answer. 
C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.- This cannot be inferred from the passage as scientific fraud is not mentioned in passage.
D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.- This is not stated in the passage
E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.- Bhaskara had no such intention while designing the overbalanced wheel

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:
A. refute the notion that perpetual motion is only possible in technological ventures- This is not mentioned in the passage
B. illustrate how only sunlight can successfully power perpetual motion cycles- the usage of 'only' sunlight makes this option wrong
C. elaborate on the definition of perpetual motion machines through apparent examples- This is not the author's intention
 D. argue that hydroelectric power plants are not, in fact, perpetual motion machines- This is the correct answer as the author discusses the carbon and hydrologic cycles in order to argue that they are not actually perpetual 
E. demonstrate that perpetual motion machines are not designed using solar energy- This is not the author's intention

4. The third paragraph supplies information for answering all of the following questions EXCEPT:
A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel?- This is stated in the passage- frag or friction in the form of heat
B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel?- 2nd law is broken
C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy?- Each time the mercury in Bhaskara’s wheel strikes the side of the containers, the impact generates heat, which is dissipated into the air and thus lost from the system.
 D. How might a machine violating the first law of thermodynamics be designed?- This is not stated in the passage. This is the correct answer. 
E. What is the purpose of the science of thermodynamics?- The science that studies the behaviour and rules of energy is thermodynamics

Ritax · Answer

Such an interesting passage, eventhough I could not imagine the picture of that wheel.

Will try my best to explain reasons behind my answer. The main idea of the passage: Author tried to point out that Bhaskara's motion is not truely perpetual. P1 : Introduction to Bhaskara's proposal and explain how it work. P2 : Definition of a perpetual motion + give example of process in nature (need external energy) carbon or hydrologic cycle - use sunlight as an energy. hydroelectic power - use power of a waterfall P3 : Point out evidence that help support author's conclusion against Bhaskara's proposal evidence about thermodynamics law 1 and 2.

Deleted Q1 Q2 Q4 explanation because incorrect answer Q3 In paragraph two, the author discusses the carbon and hydrologic cycles in order to: Ref: Paragraph 2 , carbon and hydrologic cycles was stated because the author wants to give an example of nature's perpetual motion.However, author still believe that in nature's perpetual motion still need external force to help drive. A. refute the notion that perpetual motion is only possible in technological ventures X Author only provide an example, did not use this example to refute anything. B. illustrate how only sunlight can successfully power perpetual motion cycles X Yes sunlight is a source of carbon and hydrologic cycles, but there is no such illustrate or explanation about how this thing works. C. elaborate on the definition of perpetual motion machines through apparent examples ✓ Yes , Paragraph 2 mainly use to provide premise and fact to explain what is a perpetual motion. D. argue that hydroelectric power plants are not, in fact, perpetual motion machines X not mainly use to argue because there is no such argument in this passage. E. demonstrate that perpetual motion machines are not designed using solar energy X Solar energy only provided as example

vrsthe1 · Answer

Reading for Comprehension: 
P1 - Perpetual motion machine ( PMM ) - what Bhaskara did -->  Intro to an invention.

P2 - Definition of PMM - seemingly no external power required, but works due to gravity, buoyancy, etc., and examples -->  Define PMM.

P3 - 2 types --type1 - violates first law of thermodynamics.
type2 - violates second law of thermodynamics -- Bhaskara's design & how. -->  shortcomings of PMM.

purpose of passage: to introduce, define and mention shortcomings of an invention.

Q1. The primary purpose of the passage is to: 
 A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics 
 Not correct  --> only 1 design is talked about in passage and no mention of the knowledge level.

B. show why the overbalanced wheel cannot be made to do usable work 
 Not correct  --> no mention of whether the wheel can be put to work or not.

C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine 
 Correct  --> the mention of PMM enticing inventors, but no one actually was able to make one.

D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model 
 Not Correct  --> Examples of almost possible PMM are given in para 2. but they are almost possible not a true PMM.

E. reject a design for a perpetual motion machine and propose a working alternative 
Not Correct --> did not reject or propose anything, only mentioned how PMM by Bhaskara was not possible.
--------------------------------------------------------------------------------------------------------------------

Q2. It can be inferred from the passage that:

A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel. 
 Not Correct  --> we only know about what was published, nothing about the thought or science behind it was mentioned or can be inferred.

B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles. 
 Correct  --> without 100% efficiency the machine cannot be in perpetual motion. Hence this can be inferred from 1st paragraph, which states "enabling perpetually".

C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed. 
 Not Correct  --> fraud was mentioned when mentioning about others who are enticed by the idea of PMM.

D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model. 
 Not Correct  --> we can infer that no working model was produced because nothing about experiment or model was mentioned but only the drawing. Hence without a working model inventor can believe that the PMM might work flawlessly.

E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines. 
 Not Correct  --> as it was later on from science it is understood that the PMM is not possible. Also the drawing only tells how the concept would turn perpetually without external energy but not impossibility.
---------------------------------------------------------------------------------------------------------------------

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

A. refute the notion that perpetual motion is only possible in technological ventures 
 Not Correct  --> no mention of the technological ventures.

B. illustrate how only sunlight can successfully power perpetual motion cycles 
 Not Correct  --> PMM cycle means no external power.. the statement itself is contradictory.

C. elaborate on the definition of perpetual motion machines through apparent examples 
 Correct  --> carbon and hydrologic cycles are mentioned as examples of how seemingly PMM are present in nature but are infact powered by sun.

D. argue that hydroelectric power plants are not, in fact, perpetual motion machines 
 Not Correct  --> there was no arguement but given as example how sun provides the external power to carbon & hydrologic cycles like water does for hydroelectric power plants.

E. demonstrate that perpetual motion machines are not designed using solar energy 
 Not Correct  --> no mention of nay PMM desinged using solar energy, but how seemily PMM process occurs in nature but use solar energy.
---------------------------------------------------------------------------------------------------------------------

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel? 
 Not correct  --> Mentioned. impact converted to heat.

B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel? 
 Not correct  --> Mentioned. 2nd law.

C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy 
 Not correct  --> Mentioned. As energy is dissipated as heat.

D. How might a machine violating the first law of thermodynamics be designed? 
 Correct  --> bhaskara's PMM violates 2nd law. hence the statement is not mentioned in the paragraph.

E. What is the purpose of the science of thermodynamics? 
 Not correct  --> Mentioned. Study the behavior and rules of energy.

Fido10 · Answer

1. The primary purpose of the passage is to:

A. illustrate erroneous designs of early scientists who did not possess a proper knowledge of the laws of physics 
The passage did not talk about the errors of scientists that did not possess the knowledge of the laws of physics
 B. show why the overbalanced wheel cannot be made to do usable work 
This answer, states the purpose of just the 3rd paragraph, and not the whole passage and then it is not correct
 C. discuss the pursuit and ultimate failure of inventors to design a perpetual motion machine 
This is the correct answer choice. The passage discusses essays about creating perpetual motion machines and explains/discusses the science behind it.
 D. argue that while perpetual motion cycles are possible in nature, scientists have never been able to produce a working mechanical model 
the passage did not stay that perpetual motion is possible in nature ! In contrary it says that even if it appears as a perpetual motion , it is not.
Wrong answer
 E. reject a design for a perpetual motion machine and propose a working alternative 
the passage explains why a special designs cannot be considered perpetual motion and does not provide working alternative

2. It can be inferred from the passage that: 
The passage clearly said that :  L ike the study of alchemy, the notion of perpetual motion machines has enticed inventors with the impossible for centuries; since Bhaskara’s proposal, countless designers, through either fraud or wishful thinking, claimed to have devised similar contraptions.  
So since Bhaskara’s proposal, countless designers, through either fraud or wishful thinking, claimed to have devised similar contraptions, and this simply means that Bahara's design is to demonstrate the impossibility of perpetual motion machines.
So correct  answer is E 
A. Bhaskara rejected the validity of the laws of thermodynamics when he designed the overbalanced wheel.
B. Bhaskara’s design of the overbalanced wheel included 100 percent efficiency as one of its fundamental principles.
C. Bhaskara’s design of the overbalanced wheel constituted a scientific fraud that was not revealed until centuries had passed.
D. Bhaskara believed that the overbalanced wheel would work because he had not actually produced a working model.
E. Bhaskara designed the overbalanced wheel to demonstrate the impossibility of perpetual motion machines.

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to: 
It is clearly stated that : While processes in nature such as the carbon or hydrologic cycles appear to be perpetual, they are in fact driven by the energy of the sun in the same way that a hydroelectric power plant is driven by the external power of a waterfall.
So the author is constructing a definition by giving examples,  Correct answer then is : C

A. refute the notion that perpetual motion is only possible in technological ventures
B. illustrate how only sunlight can successfully power perpetual motion cycles
C. elaborate on the definition of perpetual motion machines through apparent examples
D. argue that hydroelectric power plants are not, in fact, perpetual motion machines
E. demonstrate that perpetual motion machines are not designed using solar energy

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

A. What is the dissipative force that acts upon Bhaskara’s design of the overbalanced wheel? 
the answer to this question exists in the 3rd paragraph, When the mercury in Bhaskara’s wheel  strikes the side of the containers , which is the dissipative force, then the impact generates heat, which is dissipated into the air and thus lost from the system . Wrong Answer
 B. Which law of thermodynamics is broken by Bhaskara’s design of the overbalanced wheel? 
It is clearly stated in the 3rd paragraph that "In the case of Bhaskara’s design, the second law of thermodynamics is violated."
Wrong Answer
 C. How does Bhaskara’s design fail to achieve totally efficient recycling of energy? 
It is clearly stated that heat, which is dissipated into the air when mercury strikes, and thus lost from the system. So Because of this dissipation, the system is not 100 percent efficiency .
So we know how Bhaskara’s design fail to achieve totally efficient recycling of energy
 D. How might a machine violating the first law of thermodynamics be designed? 
This is the correct answer choice. nothing the 3rd paragraph talks about the design of a machine that violates the 1 st law of thermodynamics.
The passage said that a machine that provides more energy than it requires, violates the first law of thermodynamics, but did not talk about its design.
 E. What is the purpose of the science of thermodynamics? 
It is clearly stated on the beginning of the 3rd paragraph, the purpose of thermodynamics, which is The science that studies the behavior and rules of energy

Sajjad1994 · Answer

Competition mode is off now for this passage so everyone can see others' replies.

OAs: CBCD

All the explanations will be marked or evaluated based on the three factors.

1. Accuracy
2. Logical connection of explanations
3. Efforts put in to write up the explanation

So this is a test of your GMAT Reading comprehension accuracy + Logical thinking (whether one has got the question correct for the right reason) + Stemna to write down the explanation.

For this passage  zyt  and  pintukr  did a good job, hard luck for  Ritax

Cheers.

Sajjad1994 · Answer

Official Explanation

1. The primary purpose of the passage is to

Difficulty Level:   650-700

Explanation

Analyze the Question Stem:

The words  "primary purpose"  signal that this is a Global question.

Make a Prediction:

Look for a choice that is in line with the Purpose.

Evaluate the Answer Choices:

(C)  matches the prediction and is correct.

(A)  is incorrect because the passage is not focused on schemes of early scientists in general, but rather on the design and failure of perpetual motion machines.

(B)  is too narrow; the failure of the overbalanced wheel is mentioned in the passage, but only in reference to the author’s larger discussion of the failure of perpetual motion machines.

(D)  is a distortion of the passage; the passage states that many natural cycles appear to be perpetual but are, in fact, driven by external power sources.

(E)  is also a distortion. The passage does reject Bhaskara’s design, but no alternative proposal for a perpetual motion machine is proposed. In fact, the author discusses at length why such designs are impossible.

Answer: C

TAKEAWAY:  In a Global question, make sure to pick an answer that encompasses the author's whole scope, not just a particular detail.

2. It can be inferred from the passage that:

Difficulty Level:   700

Explanation

Research the Relevant Text:

Because the question does not refer to a specific place in the passage, use the answer choices themselves to direct the research.

Make a Prediction:

With an open-ended Inference question, avoid predicting; the answer could come from anywhere in the passage.

Evaluate the Answer Choices:

(A)  is unsupported because the passage never states whether or not Bhaskara understood the laws of thermodynamics, let alone whether he rejected them.

(B)  is correct because the final paragraph states that the overbalanced wheel violates the second law of thermodynamics by striving for 100 percent efficiency.

(C)  is unsupported; although the end of paragraph one states that many perpetual motion machines were frauds, Bhaskara’s design is never alleged to be fraudulent.

(D)  is also unsupported; although the passage states that the overbalanced wheel appeared as a drawing rather than a working model, the passage never states whether or not Bhaskara attempted to produce such a model.

(E)  is incorrect because although the passage uses the overbalanced wheel as an example of the impossibility of perpetual motion machines, the author never states that Bhaskara intended his design to be such an example.

Answer: B

TAKEAWAY:  When you can't research because the question is open-ended, research the individual answers as needed.

3. In paragraph two, the author discusses the carbon and hydrologic cycles in order to:

Difficulty Level:   600

Explanation

Analyze the Question Stem:

The words  "in order to"  signal that this is a Logic question, which asks about the why of a specific detail.

Research the Relevant Text:

Based on context, it is clear that the author discusses these cycles in order to help explain the definition of a perpetual motion machine just given.

Evaluate the Answer Choices:

(C)  matches the prediction and is the correct answer. The discussion of the carbon and hydrologic cycles is used to give details about this definition through examples that actually aren't perpetual.

(A)'s "only"  makes it sound like the author believes perpetual motion is possible outside of technological ventures. But the author believes perpetual motion is not possible at all, and explains that the carbon and hydrologic cycles only appear to be perpetual.

(B)  contradicts the passage; the fact that the carbon and hydrologic cycles are driven by sunlight indicates that they are not perpetual motion cycles.

(D)  is incorrect because the author is not arguing anything about hydroelectric plants, and is not discussing the carbon and hydrologic cycles in order to say anything about such plants. Rather, hydroelectric plants are mentioned in the passage as another example of seemingly perpetual motion machines that are in fact driven by an external power source.

(E)  is incorrect because there is no indication from the passage that solar energy is not used as a power source in any perpetual motion machine designs.

Answer: C

TAKEAWAY:  Logic questions are quite predictable. Consider the referenced detail in context, and pause to consider how it fits in with the rest of the paragraph and passage.

4. The third paragraph supplies information for answering all of the following questions EXCEPT:

Difficulty Level:   650

Explanation

Analyze the Question Stem:

The phrase  "supplies information"  signals a Detail question. Note that this is an EXCEPT question, which means the correct answer will be the choice that contains a question not explicitly answered by paragraph three.

Research the Relevant Text:

Make a Prediction:

It is impossible to predict an EXCEPT question, as there are so many things the author did not mention or do. Instead, go to the choices, research, and eliminate those that are answered by paragraph three.

Evaluate the Answer Choices:

(A)  is answered at the end of paragraph three, and is therefore incorrect. Heat from the impact between mercury and the sealed containers is the dissipative force.

(B)  is answered in paragraph three, and is therefore incorrect. Bhaskara’s design violates the second law of thermodynamics.

(C)  is discussed throughout the paragraph. Bhaskara’s design loses energy from the heat generated by the impact between the mercury and the sealed containers.

(D)  is not answered by paragraph three, and is therefore correct. Although the first law of thermodynamics is discussed and defined, the design of a machine violating the first law is never mentioned.

Finally,  (E)  is mentioned at the beginning of paragraph three, which says thermodynamics is the study of energy.

TAKEAWAY:  Don't try to predict Detail EXCEPT questions. Instead, research and eliminate the choices that are details from the passage.

VerbalBot · Answer

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During the twelfth century, the Indian author Bhaskara published a

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GMAT Reading Comprehension (RC) Questions

During the twelfth century, the Indian author Bhaskara published a

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