As a siren approaches an observer, the pitch of its sound seems to get

Question

As a siren approaches an observer, the pitch of its sound seems to get progressively higher. As it passes the observer and moves farther away from him, its pitch seemingly descends. Why does this occur, when it is apparent that the true pitch of the siren remains constant? This effect, commonly known as the Doppler effect, is attributable to the change in frequency of the siren’s sound waves relative to the observer, and relies on the theory that sound is emitted in waves. As the siren approaches, each sound wave takes less and less time to reach the observer’s ears and as it recedes, each wave takes a longer amount of time to travel back to the observer.    1 
 1. Which of the following statements is supported by the passage?

I. The Doppler effect is universally accepted by physicists.
II. The pitch from a siren moving away from an observer seems lower than it actually is.
III. The Doppler effect was proposed before the advent of electric sirens.

A. I Only
B. II Only
C. III Only
D. I and II
E. II amd III

2  
 2. The passage provides information on each of the following except

A. what happens to the relative pitch of a sound wave as its source approaches an observer
B. what happens to the relative pitch of a sound wave as its source recedes from an observer
C. the physical property of sound necessary to produce the Doppler effect
D. whether the pitch of a sound at the observer’s location is the same as its pitch while it is approaching the observer
E. the distance from the observer at which the sound is most intense

f3rn4nd44m0r1m · Answer

1o Question

This was never mentioned in the text. Eliminate options A and D.

Mentioned in the text, keep options with II

This was never mentioned in the text. Eliminate options C and E. Choose B

2o Question 
 
 "When approach, it seems to get progressively higher." Eliminate

"Its pitch seemingly descends." Eliminate

" sound is emitted in waves." is the property. Eliminate

It's not the same. The passage mention the sound seems to change with location. Eliminate

It was not said in the text.  Correct option E

Saonli · Answer

The paragraph says: This effect, commonly known as the Doppler Effect...
‘Commonly known’ , this phrase often comes to mean that it has been accepted by scientists / body of professionals

So my answer is D

HarshG7 · Answer

i dont think being commonly known can be assumed to being accepted by scientists. furthermore, nowhere in the passage does the author mentions about the doppler effect's acceptability by the scientists.

AbhishekP220108 · Answer

Then why it is mentioned commonly?

As a siren approaches an observer, the pitch of its sound seems to get

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GMAT Reading Comprehension (RC) Questions

As a siren approaches an observer, the pitch of its sound seems to get

Prep Toolkit

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

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