Among the several hundred million binary systems estimated to lie with

Question

Among the several hundred million binary systems estimated to lie within 3,000 light-years of the solar system, and thus theoretically detectable using sky-survey photographs, a tiny fraction, no more than a few hundred, belongs to a curious subclass. The radiation in these systems has a peculiar wavelength distribution that long defied explanation. Such systems register high radiation levels in the visible region of the spectrum, but some of them reach even higher levels at both shorter and longer wavelengths: in the ultraviolet region, and in the infrared and radio regions.

This odd distribution of radiation is best exemplified by the pairing of a cool red-giant star and an intensely hot small star. The smaller star maintains close physical proximity to its larger companion as the two travel around a common center. Such objects have become known as symbiotic stars. On photographic plates, only the giant star can be discerned. Evidence for the existence of the hot companion, however, has now been supplied by satellite-borne instruments that are capable of detecting ultraviolet radiation at wavelengths that are absorbed by the earth’s atmosphere (and therefore not detectable by instruments on the ground). Recently two symbiotic star systems, the first ones to be detected outside our galaxy, have been observed in the Large Cloud of Magellan, one of the satellite galaxies associated with our own.

The spectra of symbiotic stars indicate that the cool red giant is surrounded by a very hot ionized gas. The existence of the ionized gas went unexplained for several decades until satellite observations finally identified the ionizing source as the radiation from an invisible hot companion. Symbiotic stars also flare up in outbursts indicating the ejection of material in the form of a shell or a ring, reminiscent of the recurrent outbursts of a nova. Symbiotic stars may therefore present a transitory phase in the evolution of certain types of binary systems, a phase in which a substantial amount of matter transfers from the larger partner to the smaller.   1 
 A 
 1. The passage implies that symbiotic star systems differ from other binary systems in which of the following ways?

A. Symbiotically paired stars emit a radiation pattern different from that of most binary stars.
B. In symbiotic star systems, one star is the center of the other’s orbit.
C. Symbiotically paired stars are the only binary stars which are capable of exchanging matter.
D. Symbiotic star systems are more common than other binary systems.
E. Symbiotic star systems are the only binary systems that can be detected by satellite-borne instruments.

2 
 D 
 2. According to the passage, the radiation emitted by symbiotic stars is distinctive in that it

A. is visible on photographic plates.
B. consists partly of visible waves.
C. cannot be detected by satellite-borne instruments.
D. is sometimes higher at the extreme ends of the spectrum.
E. emanates primarily from the larger star.

3 
 A 
 3. According to the passage, the exchange of matter within a symbiotic system may be described as a process in which

A. the red giant becomes smaller while the small star gains mass.
B. the small star loses mass while the red giant grows larger.
C. both the red giant and the small star decrease in size.
D. both stars absorb matter emitted by the surrounding gas cloud.
E. both stars gradually return to their original gaseous state.

4 
 E 
 4. The passage as a whole can be considered an answer to which of the following questions?

A. How do binary star systems evolve into symbiotic systems?
B. Why are symbiotic stars surrounded by ionized gas?
C. What percentage of the binary star systems detected to date are symbiotic pairs?
D. Why are red giants usually accompanied by intensely hot, small stars?
E. Why do certain binary stars emit unusual radiation patterns?

RC Butler 2021  -  Practice Two RC Questions Everyday.   
Passage # 303 Date: 02-Aug-2021
 This question is a part of RC Butler 2021 .  Click here for Details

BBD · Answer

Notes:
Binary system is two stars/planets revolving around a single center of gravity present outside of both stars. Special case is symbiotic systems with 2 stars. Example- Cooled giant star and hot smaller star. On earth we experience high energy in visible spectrum but  unusual   high energy in different block of spectrum. (I dont know whether these are considered visible spectrum but something tells me that these layers are extreme) 
There are hot gases on giant start explained by presence of smaller hotter star. Matter gets transferred from cooler star to hotter star which means over the period the smaller start would get bigger.

1. The passage implies that symbiotic star systems differ from other binary systems in which of the following ways?

A. Symbiotically paired stars emit a radiation pattern different from that of most binary stars. 
B. In symbiotic star systems, one star is the center of the other’s orbit.
C. Symbiotically paired stars are the only binary stars which are capable of exchanging matter.
D. Symbiotic star systems are more common than other binary systems.
E. Symbiotic star systems are the only binary systems that can be detected by satellite-borne instruments.

Question 2

2. According to the passage, the radiation emitted by symbiotic stars is distinctive in that it

A. is visible on photographic plates.
B. consists partly of visible waves.
C. cannot be detected by satellite-borne instruments.
 D. is sometimes higher at the extreme ends of the spectrum. 
E. emanates primarily from the larger star.

Question 3

3. According to the passage, the exchange of matter within a symbiotic system may be described as a process in which

A. the red giant becomes smaller while the small star gains mass. 
B. the small star loses mass while the red giant grows larger.
C. both the red giant and the small star decrease in size.
D. both stars absorb matter emitted by the surrounding gas cloud.
E. both stars gradually return to their original gaseous state.

Question 4

4. The passage as a whole can be considered an answer to which of the following questions?

A. How do binary star systems evolve into symbiotic systems?
B. Why are symbiotic stars surrounded by ionized gas?
C. What percentage of the binary star systems detected to date are symbiotic pairs?
D. Why are red giants usually accompanied by intensely hot, small stars?
 E. Why do certain binary stars emit unusual radiation patterns?

Raghav9906 · Answer

Can someone please explain Q2? I cannot find the info which marks D as the correct answer

Sajjad1994 · Answer

Explanation

2. According to the passage, the radiation emitted by symbiotic stars is distinctive in that it

Difficulty Level:   650-700

Explanation

A. is visible on photographic plates: 
The passage mentions that on photographic plates, only the giant star can be discerned, implying that the radiation from symbiotic stars is not directly visible on photographic plates. Therefore, option A is incorrect.

B. consists partly of visible waves:  
The passage states that symbiotic stars register high radiation levels in the visible region of the spectrum, indicating that visible waves are indeed a component of the radiation emitted by symbiotic stars. Therefore, option B is partially correct.

C. cannot be detected by satellite-borne instruments: 
The passage specifically mentions that evidence for the existence of the hot companion in symbiotic star systems has been supplied by satellite-borne instruments that can detect ultraviolet radiation. This contradicts option C, making it incorrect.

D. is sometimes higher at the extreme ends of the spectrum:  
The passage describes the radiation from symbiotic stars as having a peculiar wavelength distribution. It mentions that these systems reach high radiation levels not only in the visible region but also at shorter (ultraviolet) and longer (infrared and radio) wavelengths. This supports the idea that the radiation can be higher at the extreme ends of the spectrum. Therefore, option D is correct.

E. emanates primarily from the larger star: 
The passage states that the radiation in symbiotic star systems has been identified as coming from an invisible hot companion, which implies that the radiation does not primarily emanate from the larger star. Hence, option E is incorrect.

Answer: D

Among the several hundred million binary systems estimated to lie with

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Among the several hundred million binary systems estimated to lie with

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615 to 715 in 15 Days (Ria's Strategies)

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