3000 RC Passage 8/63

[AKSTCS]

Virtually everything astronomers known about objects outside the solar system is based on the detection of photons—quanta of electromagnetic radiation. Yet there is another form of radiation that permeates the universe: neutrinos. With (as its name implies) no electric charge, and negligible mass, the neutrino interacts with other particles so rarely that a neutrino can cross the entire universe, even traversing substantial aggregations of matter, without being absorbed or even deflected. Neutrinos can thus escape from regions of space where light and other kinds of electromagnetic radiation are blocked by matter. Furthermore, neutrinos carry with them information about the site and circumstances of their production: therefore, the detection of cosmic neutrinos could provide new information about a wide variety of cosmic phenomena and about the history of the universe.
But how can scientists detect a particle that interacts so infrequently with other matter? Twenty-five years passed between Pauli’s hypothesis that the neutrino existed and its actual detection: since then virtually all research with neutrinos has been with neutrinos created artificially in large particle accelerators and studied under neutrino microscopes. But a neutrino telescope, capable of detecting cosmic neutrinos, is difficult to construct. No apparatus can detect neutrinos unless it is extremely massive, because great mass is synonymous with huge numbers of nucleons (neutrons and protons), and the more massive the detector, the greater the probability of one of its nucleon’s reacting with a neutrino. In addition, the apparatus must be sufficiently shielded from the interfering effects of other particles.
Fortunately, a group of astrophysicists has proposed a means of detecting cosmic neutrinos by harnessing the mass of the ocean. Named DUMAND, for Deep Underwater Muon (muon: n. μ介子) and Neutrino Detector, the project calls for placing an array of light sensors at a depth of five kilometers under the ocean surface. The detecting medium is the seawater itself: when a neutrino interacts with a particle in an atom of seawater, the result is a cascade of electrically charged particles and a flash of light that can be detected by the sensors. The five kilometers of seawater above the sensors will shield them from the interfering effects of other high-energy particles raining down through the atmosphere.
The strongest motivation for the DUMAND project is that it will exploit an important source of information about the universe. The extension of astronomy from visible light to radio waves to x-rays and gamma rays never failed to lead to the discovery of unusual objects such as radio galaxies, quasars, and pulsars. Each of these discoveries came as a surprise. Neutrino astronomy will doubtless bring its own share of surprises.

1. Which of the following titles best summarizes the passage as a whole?
(A) At the Threshold of Neutrino Astronomy
(B) Neutrinos and the History of the Universe
(C) The Creation and Study of Neutrinos
(D) The DUMAND System and How It Works
(E) The Properties of the Neutrino

6. The passage states that interactions between neutrinos and other matter are
(A) rare
(B) artificial
(C) undetectable
(D) unpredictable
(E) hazardous



9. According to the passage, one of the methods used to establish the properties of neutrinos was

(A) detection of photons
(B) observation of the interaction of neutrinos with gamma rays
(C) observation of neutrinos that were artificially created
(D) measurement of neutrinos that interacted with particles of seawater
(E) experiments with electromagnetic radiation

Explanations please

[arorag]

1-c,6-A, 9-D

[AKSTCS]

OA

SPOILER:
1 - A
2 - A
3 - C

[powerthelogic]

I will try only the last one. (9 Question )
The question is for properties of neutrinos ..
D -neutrinos with sea matter .. This experiment is to detect the cosmic neutrinos

read this in the second passage "since then virtually all research with neutrinos has been with neutrinos created artificially in large particle accelerators and studied under neutrino microscopes." that is what C says . so C is the one to choose.

In this passage all the questions are kind of OK. Except the last one.

[dheeraj.bhasin]

1. A - Can be seen from "Neutrino astronomy will doubtless bring its own share of surprises"

[KillGmat]

The answers according to me are A ,A, C
1)A
Using POE, i got this answer. Rest all options are confined to SOME parts of the passage.
2)A

But how can scientists detect a particle that interacts so infrequently with other matter
This sentence gives us information that interaction between neutro and other matter was infrequent or rare.

3)C

Twenty-five years passed between Pauli’s hypothesis that the neutrino existed and its actual detection: since then virtually all research with neutrinos has been with neutrinos created artificially
Look at this statement. the sentence tells us that all the neutrons created for study/experiments are created artificially

D- tells us the method DUMAND,which was used to study cosmic neutron,

But we want to know about PROPERTIES of neutrons.
SO it has to be C.

[itsme_sanket]

A,A and C last was a tricky one

[akrish1982]

My answers were
1 A
6 A
9 D
9 is incorrect

I understand my misatke. "since then virtually all research with neutrinos has been with neutrinos created artificially in large particle accelerators and studied under neutrino microscopes" - this says C.

D is incorrect as "(D) measurement of neutrinos that interacted with particles of seawater"
measurement is not stated in the para...
Time = 4:46

[mannu08]

I had chose A, C and D.

thanks killgamt for the explanation.

[lesfeaves]

I selected B,A,C