Supernovas are among the most energetic events in the universe and

Question

Supernovas are among the most energetic events in the universe and result in the complete disruption of stars at the end of their lives. Originally, the distinction between Type I and Type II supernovas was based solely on the presence or absence of hydrogen atoms (hydrogen lines). Supernovas without hydrogen lines were called Type I, while those with hydrogen lines were Type II. Subsequent analysis of many of these events revealed that this empirical classification schema instead reflected two different mechanisms for the supernova explosion.

Type I supernovas happen in binary stars—two stars that orbit closely each other—when one of the two binary stars is a small, dense, white dwarf star. If the companion star ranges too close to the white dwarf that it is orbiting, the white dwarf’s gravitational pull will draw matter from the other star. When the white dwarf acquires enough matter to become at least 1.4 times as big as the Sun, it collapses and explodes in a supernova.

Type II supernovas occur when a star, much more massive than the Sun, ends its life. When such a star begins burning out, the core of the star quickly collapses releasing amazing energy in the form of neutrinos, a kind of particle smaller than even an atom. Electromagnetic radiation—energy that is electric and magnetic—causes the star to explode in a supernova. Whereas Type I supernovas typically destroy their parent stars, Type II explosions usually leave behind the stellar core.

The classification schema regarding the mechanism for supernova explosions helps to more succinctly answer the question: Is the Sun in danger of becoming a supernova? Neither does our Sun has a companion star orbiting it nor does our Sun have the mass necessary to become a supernova. Furthermore, it will be another billion years until the Sun runs out of fuel and swells into a red giant star before going into a white dwarf form.   1 
 1. How is this passage organized?

(A) A single phenomenon is introduced and two overlapping classification schemas are contrasted.
(B) An original theory is mentioned before being overturned as a result of new findings.
(C) Two complementary mechanisms for describing a single phenomenon are discussed and a conclusion is offered.
(D) A new classification schema is described and an example of how it works is provided.
(E) Two different classification systems are outlined and a question is posed to help reconcile both.

2 
 2. It can be inferred from the passage that

(A) Classifying a Type I or Type II event based on the presence or absence of hydrogen is not necessarily incompatible with a classification schema based on the mechanism by which these two events explode.
(B) A dense white dwarf’s gravitational pull on its companion star causes the companion star to collapse and explode as a supernova.
(C) Before a star such as the Sun can become a red giant, it must first become a white dwarf.
(D) In a Type II supernova, energy and electromagnetic radiation causes a star to collapse and explode.
(E) Supernovas are rare events in our universe.

3 
 3. Which of the following best summarizes the author’s answer to the question: Is the Sun in danger of becoming a supernova?

(A) The Sun is too large to have a white dwarf as a partner and lacks the physical size required to become a red giant.
(B) Even if the Sun were paired with a white dwarf, the Sun does not have the mass necessary to create sufficient electromagnetic radiation.
(C) The Sun is not a white dwarf with a companion star orbiting it, nor does it have the size to qualify as a Type II supernova.
(D) Without a white dwarf orbiting the Sun, the Sun has no obvious way to increase its size to become a Type II supernova.
(E) The Sun will inevitably become a supernova once it passes from a red giant to white dwarf but not for at least a billion years.

4 
 4. According to the passage, which statement or statements below are true?

I. The energy created from a Type II explosion is greater than the energy created by a Type I explosion.
II. The sun is not a binary star.
III. Both Type I and Type II supernovas result in the complete destruction of the exploding star.

(A) I only
(B) II only
(C) I and III only
(D) II and III only
(E) I, II, and III

Source: Chili Hot GMAT

Carcass · Accepted Answer

D A C B  are the OA.

D

The new schema is based on the distinction between Type I and Type II supernovas; the original 
schema is one based on the absence of hydrogen (Type I) or the presence of hydrogen (Type II). The 
example of the Sun is provided as support for how the classification system works. Choice D best 
summarizes this structure.

A

this one is maybe the trickiest. we have from the passage  Electromagnetic radiation — energy that is electric and 
magnetic — causes the star to explode in a supernova.   and not  In a Type II supernova, energy and electromagnetic radiation causes a star to collapse 
and explode. . Electromagnetic = energy + magnetic not energy and electromagnetic = radiation

C

Answer choice C describes accurately and completely the author’s view in the final paragraph. The 
Sun is not a binary star because it doesn’t have companion star orbiting it, so it can’t qualify as a Type 
I supernova. Nor does the Sun have the size necessary to become a Type II supernova (it would have to 
be at least 1.4 times its own size).

B

A take away here is this: even though there isn't a main idea question on the passage is worth to ask yourself ALWAYS what is the topic, scope, and purpose of the passage. The topic is supernovas. 
The scope is Type I and Type II supernovas. The purpose is to describe a new schema for classifying Type I and Type II supernovas.

eeshan89 · Answer

Here are my answers:

1. How is the passage organized?
Ans: E) Two different classification systems are outlined and a question posed to help
reconcile both.

2. It can be inferred from the passage that
Ans: D) In a Type II supernova, energy and electromagnetic radiation causes a star to collapse
and explode.

3. Which of the following best summarizes the author’s answer to the question: Is the Sun in
danger of becoming a supernova?
Ans: E) The Sun will inevitably become a supernova once it passes from a red giant to white
dwarf but not for at least a billion years.

4. According to the passage, which statement or statements below are true?
I. The energy created from a Type II explosion is greater than the energy created by a
Type I explosion.
II. The sun is not a binary star.
III. Both Type I and Type II supernovas result in the complete destruction of the exploding
star.
Ans: B) II only
Explanation: I. Nowhere in the passage does the author compare the magnitude of energies released from Type I or Type II explosions. - FALSE
II. In the last paragraph, the author mentions the fact that there is no companion star orbiting the Sun, hence, it is not a binary star. - TRUE
III. In the second last paragraph, the author mentions: "Whereas Type I supernovas
typically destroy their parent stars, Type II explosions usually leave behind the
stellar core." - FALSE

Please post the OA's and let me know if my answers are correct.

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Supernovas are among the most energetic events in the universe and

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Supernovas are among the most energetic events in the universe and

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