Imagine that we stand on any ordinary seaside pier, and watch the wave

Question

New Project RC Butler 2019  -  Practice 2 RC Passages Everyday   
Passage # 209, Date : 16-Jul-2019
 This post is a part of New Project RC Butler 2019 .  Click here for Details

Imagine that we stand on any ordinary seaside pier, and watch the waves rolling in and striking against the iron columns of the pier. Large waves pay very little attention to the columns—they divide right and left and re-unite after passing each column, much as a regiment of soldiers would if a tree stood in their way; it is almost as though the columns had not been there. But the short waves and ripples find the columns of the pier a much more formidable obstacle. When the short waves impinge on the columns, they are reflected back and spread as new ripples in all directions. To use the technical term, they are “scattered.” The obstacle provided by the iron columns hardly affects the long waves at all, but scatters the short ripples.

We have been watching a working model of the way in which sunlight struggles through the earth’s atmosphere. Between us on earth and outer space the atmosphere interposes innumerable obstacles in the form of molecules of air, tiny droplets of water, and small particles of dust. They are represented by the columns of the pier.

The waves of the sea represent the sunlight. We know that sunlight is a blend of lights of many colors—as we can prove for ourselves by passing it through a prism, or even through a jug of water, or as Nature demonstrates to us when she passes it through the raindrops of a summer shower and produces a rainbow. We also know that light consists of waves, and that the different colors of light are produced by waves of different lengths, red light by long waves and blue light by short waves. The mixture of waves which constitutes sunlight has to struggle through the obstacles it meets in the atmosphere, just as the mixture of waves at the seaside has to struggle past the columns of the pier. And these obstacles treat the light waves much as the columns of the pier treat the sea-waves. The long waves which constitute red light are hardly affected, but the short waves which constitute blue light are scattered in all directions.

Thus, the different constituents of sunlight are treated in different ways as they struggle through the earth’s atmosphere. A wave of blue light may be scattered by a dust particle, and turned out of its course. After a time a second dust particle again turns it out of its course, and so on, until finally it enters our eyes by a path as zigzag as that of a flash of lightning. Consequently, the blue waves of the sunlight enter our eyes from all directions. And that is why the sky looks blue.   1 
 C 
 1. We know from experience that if we look directly at the sun, we will see red light near the sun. This observation is supported by the passage for which one of the following reasons?

(A) It seems reasonable to assume that red light would surround the sun because the sun is basically a large fireball.
(B) It seems reasonable to assume that the other colors of light would either cancel each other or combine to produce red.
(C) It seems reasonable to assume that red light would not be disturbed by the atmospheric particles and would consequently reach us by a relatively direct path from the sun to our eyes.
(D) It is not supported by the passage. The author does not say what color of light should be near the sun, and he provides no reasons that would allow us to assume that the light would be red.
(E) Gazing directly at the sun forces the eye to focus on the longer red waves.

2 
 D 
 2. Scientists have observed that shorter wavelength light has more energy than longer wavelength light. From this we can conclude that

(A) red light will exert more energy when it hits the surface of the earth than will blue light.
(B) lightning is caused by the collision of blue light with particles in the air.
(C) red light will travel faster than blue light.
(D) blue light has more energy than red light.
(E) blue light has less energy than red light.
 3 
 D 
 3. A scientist makes new observations and learns that water waves of shorter wavelengths spread in all directions not only because they scatter off piers but also because they interact with previously scattered short water waves. Drawing upon the analogy between water waves and light waves, we might hypothesize which of the following?

(A) Blue light waves act like ripples that other blue light waves meet and scatter from.
(B) Red light waves will be scattered by blue light waves like incoming long water waves are scattered by outgoing ripples.
(C) Red light waves can scatter blue light waves, but blue light waves cannot scatter red.
(D) The analogy between water and light waves cannot be extended to include the way in which short water waves become ripples and scatter one another.
(E) The scattering effect of blue light waves is canceled by that of red.

4 
 B 
 4. Which one of the following is a reason for assuming that sunlight is constituted of waves of many colors?

(A) The mixture of waves that make up sunlight has to struggle through a variety of obstacles in the atmosphere.
(B) When passing through water in the atmosphere, sunlight is sometimes broken down into an array of colors.
(C) Many different wavelengths of light enter our eyes from all directions.
(D) The mere fact that light waves can be scattered is a reason for assuming that sunlight is constituted of waves of different colors.
(E) When passing through dust in the atmosphere, sunlight is sometimes broken down into an array of colors.

5 
 D 
 5. From the information presented in the passage, what can we conclude about the color of the sky on a day with a large quantity of dust in the air?

(A) The sky would be even bluer
(B) The sky would be redder
(C) The sky would not change colors
(D) We do not have enough information to determine a change in color
(E) The sky would assume a violet hue

6 
 C 
 6. We all know that when there is a clear sky, the western sky appears red as the sun sets. From the information presented in the passage, this phenomenon would seem to be explained by which of the following?

I.  Light meets more obstacles when passing parallel to the earth’s surface than when traveling perpendicular. Consequently, even red light is diffused.
 II.  The blue light may not make it through the denser pathway of the evening sky, leaving only the long light waves of red.
 III.  The short red light waves have more energy and are the only waves that can make it through the thick atmosphere of the evening sky.

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

7 
 D 
 7. Which one of the following does the author seem to imply?

(A) Waves of light and waves of water are identical.
(B) Waves of light have the same physical shape as waves of water.
(C) Waves of light and waves of water do not have very much in common.
(D) Waves of water are only models of waves of light.
(E) There are colors of light waves just as there are colors of water waves.

Source:   Nova GMAT  
Difficulty Level:   700

Sajjad1994 · Accepted Answer

Hi Dear  ssaamm 
 vishumangal 
 Verbal33

May your doubts get cleared.

Official Explanation

3. A scientist makes new observations and learns that water waves of shorter wavelengths spread in all directions not only because they scatter off piers but also because they interact with previously scattered short water waves. Drawing upon the analogy between water waves and light waves, we might hypothesize which of the following?

Explanation

This is an application question since it introduces new information about water waves and asks us to conclude how the behavior of light waves might be similarly affected. Given this information, however, we can justify no conclusion about whether light waves imitate water waves in this new regard. The analogy might hold or it might break down. We don’t yet know. (To find out we would have to do an experiment using light.)

The answer is (D).

5. From the information presented in the passage, what can we conclude about the color of the sky on a day with a large quantity of dust in the air?

Explanation

(A):  No. Although dust is mentioned as one of the three important obstacles  (lines 16–17) , we simply do not have enough information to conclude how dust density would change sky color.

(B):  No. While this idea may fit with the common lore that a lot of dust in the air creates great, red sunsets, the passage itself gives no basis to any conclusion regarding color change.

(C):  No. Same reason as in  (A) and (B).

(D):  Yes. There is not enough information in the passage to determine a relationship between color change and dust density. The dust may give off a certain color of its own—we can’t say for certain.

The answer is (D).

6. We all know that when there is a clear sky, the western sky appears red as the sun sets. From the information presented in the passage, this phenomenon would seem to be explained by which of the following?

Explanation

Statement I is true.  There are obviously more particles on a horizontal than a vertical path. The glowing red sky is reasonable evidence for some diffusion. Note that  Question 5  asks  “what can we conclude”  while this question asks what seems plausible (what  “would seem to be explained” ). So, while we are attempting to make very similar inferences in both questions, what we can do with the data depends, among other things, on the degree of certainty requested.

Statement II is true . The path of evening light probably has a greater average density, since it spends more time passing through a zone of thicker atmosphere. It is reasonable to assume this significantly greater density, or the absolute number of particles, might present an obstacle to blue light.

Statement III is false.  There are two things wrong with this answer: (1) red light waves are not short, relative to blue; (2) we do not know that waves with more energy will more readily pass through obstacles. The passage, in fact, implies just the opposite.

The answer is (C).

7. Which one of the following does the author seem to imply?

Explanation

(A):  No. Water waves offer only a model for light waves. As a model, they are identical in some ways but not in others.

(B):  No. This is not implied by the passage. What they have in common is the way they act when they impinge on obstacles.

(C):  No. Waves of water are used as a model because they have much in common with waves of light.

(D):  Yes. See explanation for  (A).

The answer is (D).

Hope it helps

ssaamm · Answer

getting stuck in ques 5,6,7
in ques 5 i think D to be more appropriate as there is no where montioned about density increase or decrease will lead to what?
in ques 7 how can we state that waves of water are only model.use of extreme word such as only should be explicitly mentioned in the passage to be true.so how can we imply this

vishumangal · Answer

Could someone explain me the ans for ques 6 as there is no where mentioned in the passgae that light meet more obstacles when travel.parallel to earth surface then when traveling perpendicular

Posted from my mobile device

Verbal33 · Answer

For question number 3 why answer A is incorrect??

Qs. A scientist makes new observations and learns that water waves of shorter wavelengths spread in all directions not only because they scatter off piers but also because they interact with previously scattered short water waves. Drawing upon the analogy between water waves and light waves, we might hypothesize which of the following?

In question stem its asking about the analogy and what we might hypothesize. So how can we say that we cannot conclude??

Can anyone explain?

zoezhuyan · Answer

anyone can help Q4?
 and what the difficult level of each questions?

Sajjad1994 · Answer

Official Explanation

4. Which one of the following is a reason for assuming that sunlight is constituted of waves of many colors?

Difficulty Level:   650

Explanation

(A):  No. We do not know anything about a “variety” of obstacles; even if we did, we would have no reason to assume that light is constituted of different colors.

(B): Yes.   See lines  (We know that sunlight is a blend of lights of many colors—as we can prove for ourselves by passing it through a prism, or even through a jug of water, or as Nature demonstrates to us when she passes it through the raindrops of a summer shower and produces a rainbow) . Rainbows occur because light is constituted of many colors.

(C):  No. This is a distortion of lines 49–51, and it sounds illogical to boot.

(D):  No. This gives no reason to assume that light is constituted of many colors.

(E):  No. Water vapor in the atmosphere causes rainbows, not dust.

Answer: B

Difficulty Level of each question

1. 550
2. 550
3. 750
4. 650
5. 700
6. 750
7. 700

Overall: 700

Hope it helps

zoezhuyan · Answer

hi  SajjadAhmad  and other experts, 
would you please calcify what the difference between 
 D) The mere fact that light waves can be scattered is a reason for assuming that sunlight is constituted of waves of different colors. 
and 
 Consequently, the blue waves of the sunlight enter our eyes from all directions B When passing through water in the atmosphere, sunlight is sometimes broken down into an array of colors.  because I think B actually is the same meaning as the sunlight is a blend of lights of many colors, it is common sense that different color light has different wavelengths. 
 how can we use the assumption itself as the reason of the assumption?

ShankSouljaBoi · Answer

Q7 D option uses the word ONLY in a very subtle manner. Note to self : The option does not mean that the model of waves is the  only  comparable model for the proposed analogy drawn by the scientist.

HarryStamper · Answer

Option I in Question 6 states "Light meets more obstacles when passing parallel to the earth’s surface than when traveling perpendicular. Consequently,  even  red light is diffused". Key word 'even'. Does this not suggest that even blue light will be scattered? Therefore, shouldn't the sky be a mix of red and blue (not what the question prompt suggests)? Option II is a lot clearer as it says that blue light may not make it through, leaving only red.

chetan2u  and  TommyWallach : please can you weigh in? Thanks.

Jks3000 · Answer

Don't trust OA, they are highly debatable

Harsh9676 · Answer

Hey

Why is this passage so tough?

I saw a question asking support from passage and the answer to that is It cannot be concluded from passage? Never seen such Qs.

VerbalBot · Answer

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Imagine that we stand on any ordinary seaside pier, and watch the wave

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