Electricity is produced from several sources e.g. hydro-electric power

Question

Electricity is produced from several sources e.g. hydro-electric power is electricity produced from water resources generally by building dams; solar power is electricity produced by converting heat energy of the sun into electrical energy; thermal energy is electricity produced by burning coal or natural gas, etc.

Nuclear energy is one of the sources of electricity and is produced in a nuclear reactor. A nuclear reactor produces and controls the release of energy from splitting the atoms of elements such as uranium and plutonium. In a nuclear power reactor, the energy released from continuous fission of the atoms in the fuel as heat is used to make steam. The steam is used to drive the turbines which produce electricity (as in most fossil fuel plants, but without the combustion of fossil fuels (high-carbon) and resultant greenhouse gas emissions).

If graphite or heavy water is used as moderator, it is possible to run a power reactor on natural instead of enriched uranium. Natural uranium has the same elemental composition as when it was mined (0.7% U-235, over 99.2% U-238), enriched uranium has had the proportion of the fissile isotope (U-235) increased by a process called enrichment, commonly to 3.5 - 5.0%. In this case the moderator can be ordinary water, and such reactors are collectively called light water reactors.

As of 2005, nuclear power provided 6.3% of the world's energy and 15% of the world's electricity, with the U.S., France, and Japan together accounting for 56.5% of nuclear generated electricity.Nuclear power poses many threats to people and the environment. These threats include the problems of processing, transport, and storage of radioactive nuclear waste, the risk of nuclear weapons proliferation and terrorism, as well as health risks and environmental damage from uranium mining. Besides, Reactors themselves are enormously complex machines where many things can and do go wrong; and there have been serious nuclear accidents.

In addition, against the belief of many proponents of nuclear energy, when all the energy-intensive stages of the nuclear fuel chain are considered, from uranium mining to nuclear decommissioning, nuclear power is neither a low-carbon nor an economical electricity source.

Some serious nuclear and radiation accidents like the Chernobyl disaster, Fukushima Daiichi nuclear disaster, and the Three Mile Island accident highlight the dangers associated with the proliferation of nuclear power. While some proponents claim that Nuclear power has caused far fewer accidental deaths per unit of energy generated than other major forms of power generation, they consider only the past data and fail to look at the potential of damage from nuclear reactors in case of major earthquakes or natural disasters. Besides, even as per the current available data, nuclear power plant accidents rank first in terms of their economic cost, accounting for 41 percent of all property damage attributed to energy accidents. Source: e-GMAT

zhanbo · Answer

1.  For each of the following, select Justified if it is a justified inference on the basis of the information provided. Otherwise select Not Justified.

Enriched uranium produces more energy per gram than natural uranium -  Not Justified  
We only know "If graphite or heavy water is used as moderator, it is possible to run a power reactor on natural instead of enriched uranium." Information on their respective productivity is not provided and cannot be inferred.

Nuclear electricity production is similar to electricity production from fossil fuels in away that both uses heat energy to produce electricity -  Justified. 
Supported by the following sentences: "In a nuclear power reactor, the energy released from continuous fission of the atoms in the fuel as heat is used to make steam. The steam is used to drive the turbines which produce electricity (as in most fossil fuel plants, ..."

Nuclear power has caused fewer accidental deaths than any other form of power generation. -  Not Justified. 
This is a   very tricky   question. I initially think it is not justified, then I changed the mind. Ultimately, I am back to "Not justified". 
We are told that "Nuclear power has caused far fewer accidental deaths per unit of energy generated than other  major  forms of power generation"
We are also told that "As of 2005, nuclear power provided 6.3% of the world's energy". So, it seems that Nuclear power has caused fewer accidental deaths? 
But we have to take notice of " major  forms of power generation".
There are also minor or negligible forms of power generation. Those forms of power generation may see only a few, if any, human causalities. We cannot infer that Nuclear power has caused fewer accidental deaths than any other form of power generation.

2  The following statements are claims of the proponents of nuclear energy. Mark each of them as Tackled, if they have been directly countered by the opponent, otherwise mark Not Tackled

Almost all the world’s developed countries use nuclear energy as a source of electricity -  Not tackled  
Because the opponents do not address this claim.

Nuclear energy produces less greenhouse gas and is also a cheap alternative to other sources of electricity -  Tackled 
Note this sentense:
"In addition, against the belief of many proponents of nuclear energy, when all the energy-intensive stages of the nuclear fuel chain are considered, from uranium mining to nuclear decommissioning, nuclear power is neither a low-carbon nor an economical electricity source."

The number of deaths in the nuclear reactors so far does not exceed even 1% of the total deaths caused by other sources of electricity -  Not tackled. 
The opponent does not discuss this statement.

3.  Which of the following statement,  if true,  would be the strongest counter-argument to the argument of the opponent regarding the data of fewer accidental deaths per unit of nuclear energy?
My answer is  (A) . 
Note the argument of the opponent regarding the data of fewer accidental deaths per unit of nuclear energy: It is true that Nuclear power has caused far fewer accidental deaths per unit of energy generated than other major forms of power generation, but they consider only the past data and  fail to look at the potential of damage from nuclear reactors in case of major earthquakes or natural disasters .
Now, if (A) is true, "In case of major earthquakes or natural disasters, the number of deaths in a nuclear power plant has always been lower than the number of deaths in a similar size power plant of any other source of electricity." The opponents' argument does not hold.

(B) Irrelevant. It provides some background information only.
(C) Irrelevant. Being compensated by insurance for lives lost does not necessarily counter opponent's argument. (Note the use of "due to" in this sentence is considered incorrect in GMAT)
(D) The opponent does not question the past data but warn about the future catastrophes. 
(E) This one directly contradicts the information in the prompt. In GMAT test, it is highly unlikely that newly introduced info should contradict premises.

Sajjad1994 · Answer

Competition mode is off now.

OAs are:

Question #1

All Not Justified

Question #2

Not Tackled, Tackled, and Not Tackled

Question #3

A

zhanbo · Answer

Hmm, while I am not ready to claim that my answers are totally  justified , it is rather obvious that not all QAs are correct. 
Will you please  tackle  question 1 and 2 and explain your answers? 
Thanks!

Sajjad1994 · Answer

Explanation

1. For each of the following, select Justified if it is a justified inference on the basis of the information provided. Otherwise select Not Justified.

Justified    Not Justified    Statements   
      Enriched uranium produces more energy per gram than natural uranium  
      Nuclear electricity production is similar to electricity production from fossil fuels in away that both uses heat energy to produce electricity        Nuclear power has caused fewer accidental deaths than any other form of power generation

Statement 1:

This statement belongs to Paragraph 3 from Tab 1;

"If graphite or heavy water is used as moderator, it is possible to run a power reactor on natural instead of enriched uranium. Natural uranium has the same elemental composition as when it was mined (0.7% U-235, over 99.2% U-238), enriched uranium has had the proportion of the fissile isotope (U-235) increased by a process called enrichment, commonly to 3.5 - 5.0%. In this case the moderator can be ordinary water, and such reactors are collectively called light water reactors."

The above is the related text and from the text, we cannot infer whether or not Enriched uranium produces more energy per gram than natural uranium.

Not Justified

Statement 2

This statement talks about only the intersection of Nuclear electricity production and electricity production. Support from the passage can be found from paragraph two of Tab 1:

"In a nuclear power reactor, the energy released from continuous fission of the atoms in the fuel as heat is used to make steam. The steam is used to drive the turbines which produce electricity (as in most fossil fuel plants,   but without the combustion of fossil fuels   (high-carbon) and resultant greenhouse gas emissions).

In the first half of the text above it seems the statement can be inferred but the problem starts from  "but without the combustion of fossil fuels"  which makes it doubtful so we have no surety whether we can infer it accurately and with surety or not.

Not Justified

Statement 3

We don't have enough data to prove that so we can not infer this information.

Not Justified

Answer:
  All Not Justified.

Sajjad1994 · Answer

Explanation

2. The following statements are claims of the proponents of nuclear energy. Mark each of them as Tackled, if they have been directly countered by the opponent, otherwise mark Not Tackled

Tackled    Not Tackled    Statements   
      Almost all the world’s developed countries use nuclear energy as a source of electricity  
      Nuclear energy produces less greenhouse gas and is also a cheap alternative to other sources of electricity  
      The number of deaths in the nuclear reactors so far does not exceed even 1% of the total deaths caused by other sources of electricity

Statement 1

This question belongs to Tab 2 and by reading even the complete question we cannot infer that the opponents of nuclear energy have countered this statement. so the answer is:

Not Tackled

Statement 2

This statement has been countered by the opponent of nuclear energy in the words:

In addition, against the belief of many proponents of nuclear energy, when all the energy-intensive stages of the nuclear fuel chain are considered, from uranium mining to nuclear decommissioning, nuclear power is neither a low-carbon nor an economical electricity source.

So the answer is:

Tackled

Statement 3

The exact number of deaths or the comparative rate of deaths has not been countered by the opponents of nuclear energy. So the answer is:

Not Tackled

Answer:
  Not Tackled, Tackle, and Not Tackled

Sajjad1994 · Answer

Explanation

3. Which of the following statement would be the strongest counter-argument to the argument of the opponent regarding the data of fewer accidental deaths per unit of nuclear energy?

A. In case of major earthquakes or natural disasters, the number of deaths in a nuclear power plant has always been lower than the number of deaths in a similar size power plant or any other source of electricity.

This statement seems logical so let's keep it for now and move on to others

B. In case of major earthquakes or natural disasters, the accidental deaths in a nuclear power plants are primarily due to heat energy accumulated in the plant.

This is rather opposite as this statement is saying indirectly that the opponent of nuclear energy are indeed correct and the nuclear energy is a thread and dangerous this statement is strengthening the opponents view.

C. Due to the extensive insurance coverage of all the nuclear plants, all the victims in a natural disaster are paid sufficient amounts by the insurance companies.

Same as  (a)  strengthening the view of opponents of nuclear energy in some other angle.

D. Past data cannot be challenged since it has been verified by the concerned government agencies.

This is not a logical answer it is merely a polar opposite of what is stated above.

E. Even if the number of deaths per unit of power produced is greater in nuclear energy, no one can deny the environmental benefits of nuclear power.

This is induction information that is half true and half false.

So best option is  A  and support of which can be found in the text below:

"Besides, even as per the current available data, nuclear power plant accidents rank first in terms of their economic cost, accounting for 41 percent of all property damage attributed to energy accidents."

Answer  option (A)  is basically weakening the above quoted text and the same is required by question.

Answer: A

Sk1003 · Answer

Hey I'm still not clear on why Statement 2 on Q1 is not justified. You said "but the problem starts from "but without the combustion of fossil fuels" which makes it doubtful". What's the problem and doubt though? The stem clearly states that it uses heat in form of steam like most fossil fuel plants. Can you please elaborate?

Any expert replies here would help

Any expert replies here would help

Cowtommi · Answer

I think  "but without the combustion of fossil fuels"  does not make Q2 doubful, rather regardless.

Fossil fuels use heat energy becuase fossil fuels needs to be burned to make an energy. This is not a controversal.
 (so heat is a cause, not a result.)

Fossil fuels does not generate heat itself. Fossil fuels needs to be heated to use fuels, as we start engine by ignition of a gas car to use gas fuel.

However, nuclear power reactor does not use heat to make an energy.

Heat is the result from continuous fission of the atoms in the fuel.
 (so heat is a result, not a cause.)

According to the passage, natural uranium or enriched uranium is the fuel of nuclear energy.

bb · Answer

I don't see how "not justified" is the correct answer to the second answer choice. Here it says "both uses heat energy to produce electricity" - the heat may have been derived in different ways (one is chemically and one through a chain reaction), both generate heat which is then used to power turbines with steam. I am not sure what the test writer was trying to achieve and what trap they tried to set, but I am not seeing the distinction based on JUST the answer choice statement. Both use heat energy

By the way, I am not sure if copying was done poorly or this question has grammatical errors - either way it does not help (e.g. both uses instead of both use).

Dbrunik · Answer

due to this ambiguity, would you consider this a low quality question?

Dbrunik · Answer

This is a low quality question. both nuclear and fossil fuel power plants generate electricity by converting heat into electric energy.

they do, however, have different sources of said heat. Both real life and the passage actually support this, so this question is either low quality or it is in error.

Sanoshmishra · Answer

Who makes up these dumb questions?

yazlal25 · Answer

in Question 1, why is the 2nd answer not justified ?

Nuclear electricity production is similar to electricity production from fossil fuels in a way that both uses heat energy to produce electricity - Not Justified ?

"  In a nuclear power reactor, the energy released from continuous fission of the atoms in the fuel as heat is used to make steam. The steam is used to drive the turbines which produce electricity (as in most fossil fuel plants, but without the combustion of fossil fuels (high-carbon) and resultant greenhouse gas emissions)" - I think this justifies it...

kartickdey · Answer

could not understand the explanation for statement 1. Enriched uranium has more percentage of fissile element per gram. so it will definitely produce more energy per gram than natural uranium

Bunuel · Answer

Archiving this question. Not precise wording.

Tackled	Not Tackled
		Almost all the world’s developed countries use nuclear energy as a source of electricity.
		Nuclear energy produces less greenhouse gas and is also a cheap alternative to other sources of electricity.
		The number of deaths in the nuclear reactors so far does not exceed even 1% of the total deaths caused by other sources of electricity.

Electricity is produced from several sources e.g. hydro-electric power

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My Rewards

Justified	Not Justified
		Enriched uranium produces more energy per gram than natural uranium.
		Nuclear electricity production is similar to electricity production from fossil fuels in a way that both uses heat energy to produce electricity.
		Nuclear power has caused fewer accidental deaths than any other form of power generation.

	In case of major earthquakes or natural disasters, the number of deaths in a nuclear power plant has always been lower than the number of deaths in a similar size power plant of any other source of electricity.
	In case of major earthquakes or natural disasters, the accidental deaths in a nuclear power plants are primarily due to heat energy accumulated in the plant.
	Due to the extensive insurance coverage of all the nuclear plants, all the victims in a natural disaster are paid sufficient amounts by the insurance companies.
	Past data cannot be challenged since it has been verified by the concerned government agencies.
	Even if the number of deaths per unit of power produced is greater in nuclear energy, no one can deny the environmental benefits of nuclear power.

Justified	Not Justified	Statements
		Enriched uranium produces more energy per gram than natural uranium
		Nuclear electricity production is similar to electricity production from fossil fuels in away that both uses heat energy to produce electricity
		Nuclear power has caused fewer accidental deaths than any other form of power generation