Which of the following statements is (are) NOT correct? i. pressure changes do not affect the speed of sound in air ii. the velocity of sound increases with temperature iii. the quality of the note depends only on its frequency
i only
ii only
iii only
i and iii
ii and iii
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Discussions (24)
The answer is C no doubt beacuse the speed of the sound is only affected by the squareroot of absolute temperature and density of the medium
Thus Velocity if sound wave is proportional to both density of medium and the squareroot and absolute temperature
The quality or timbre of a sound depends only on the source such as overtone and harmonics
Ans us C.. .
Pressure does not affect speed ofsound...
...the quality if a note depends on harmonics
The statement i. "pressure changes do not affect the speed of sound in air" is NOT correct.
In fact, the speed of sound in air is directly proportional to the square root of the absolute temperature, and inversely proportional to the square root of the molar mass of the gas. This means that changes in pressure, temperature, and humidity can all affect the speed of sound in air.
The statement ii. "the velocity of sound increases with temperature" is correct.
As the temperature of the medium (air, in this case) increases, the speed of sound also increases because the molecules in the medium vibrate faster and transfer the sound energy more quickly.
The statement iii. "the quality of the note depends only on its frequency" is NOT correct.
The quality or timbre of a sound is determined not only by its frequency but also by its harmonics, which are multiples of the fundamental frequency. The relative amplitudes and timing of these harmonics give different sounds their unique qualities.
So the answer is D
iii. The quality of the note depends only on its frequency:
This statement is NOT CORRECT. The quality (or timbre) of a sound depends on the number and relative intensity of overtones (harmonics) present. It is what allows you to distinguish between a piano and a violin playing the same note. Pitch is the property that depends primarily on frequency.
myschool, the correct answer ought to be C.
Statement iii is incorrect because the quality (or timbre) of a musical note does not depend on frequency; rather, it depends on the overtones (harmonics) and the resulting waveform. Frequency determines the pitch of the sound, not its quality.
Statement I is correct. In an ideal gas approximation, pressure changes do not affect the speed of sound because pressure and density change proportionally at a constant temperature, effectively canceling each other out.
Let's analyze each statement carefully:
1. Statement (i): "Pressure changes do not affect the speed of sound in air."
This is correct under constant temperature. The speed of sound in an ideal gas depends on temperature, not on pressure, because both pressure and density change proportionally in air.
2. Statement (ii): "The velocity of sound increases with temperature."
This is correct. The speed of sound in air is given by:
v = \sqrt{\frac{\gamma R T}{M}}
3. Statement (iii): "The quality of the note depends only on its frequency."
This is incorrect. The quality (or timbre) of a sound is determined by the presence of overtones and harmonics in addition to frequency. Different musical instruments can produce the same frequency but still sound different due to their harmonic content.
Answer:
The incorrect statements are (iii) only.
Thus, the correct option is:
C. iii only.
answer is B.....quality of a note depend on the overtones which is multiple of his fundamental frequency and sound waves are produced through the compression(pressure above normal) and rarefaction(pressure below the normal) of the air by vibrating bodies. so the speed of sound will vary with different pressure
The correct answer is option B. Pressure ideally does not affect the speed of sound in air. And, the quality of sound/timbre depends on the overtones/harmonics, while the pitch of a sound depends on the frequency of the note produced. Thank you.
