Consider the following statements about 'Note' and 'Noise': 1. A note is a sound that is pleasant to listen to. 2. Noise is produced by a mixture of several frequencies that is unpleasant to the ear. 3. A note is produced by a single frequency. Which of the statements given above is/are correct?

Correct Option The correct option is 1 only. Explanation Sounds are classified as notes or noise based on the nature of vibrations, frequency composition, and their perception by the human ear. Statement-wise Analysis - Statement 1: Correct. A note is defined as a sound that is pleasant to listen to and is produced by regular, periodic vibrations. - Statement 2: Incorrect. Noise is unpleasant to the ear, but it is characterised by irregular vibrations and does not necessarily imply a simple mixture of several distinct frequencies. - Statement 3: Incorrect. A note is not produced by a single frequency alone; it consists of a fundamental frequency along with its harmonics, making it a combination of frequencies. Key Takeaway: A note is a pleasant sound produced by regular vibrations and consists of a fundamental frequency along with harmonics, whereas noise arises from irregular vibrations.

Consider the following statements about 'Note'… - NCERT Class 9 Science MCQ

NCERT Class 9 Science — Chapter 5: Sound

mcqmedium

Consider the following statements about 'Note' and 'Noise':

A note is a sound that is pleasant to listen to.
Noise is produced by a mixture of several frequencies that is unpleasant to the ear.
A note is produced by a single frequency.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Science - class 9 · Page 6

Options

A1 only
B2 only
C1 and 3 only
D1, 2 and 3

Did you get this right?

Solution

Correct Option

The correct option is 1 only.

Explanation

Sounds are classified as notes or noise based on the nature of vibrations, frequency composition, and their perception by the human ear.

Statement-wise Analysis

Statement 1: Correct. A note is defined as a sound that is pleasant to listen to and is produced by regular, periodic vibrations.
Statement 2: Incorrect. Noise is unpleasant to the ear, but it is characterised by irregular vibrations and does not necessarily imply a simple mixture of several distinct frequencies.
Statement 3: Incorrect. A note is not produced by a single frequency alone; it consists of a fundamental frequency along with its harmonics, making it a combination of frequencies.

Key Takeaway: A note is a pleasant sound produced by regular vibrations and consists of a fundamental frequency along with harmonics, whereas noise arises from irregular vibrations.

Your note

More from Chapter 5: Sound

Consider the following statements about the 'Hearing Aid': 1. It is a battery-operated electronic device. 2. The microphone converts electrical signals into sound. 3. The speaker converts sound waves into electrical signals. Which of the statements given above is/are correct?

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What is the primary purpose of designing curved ceilings in concert halls and cinema halls?

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"A violin and a flute may be played at the same time... but the sounds we receive are different." This difference is primarily due to which characteristic of sound?

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With reference to the audible range of sound, consider the following statements: 1. The audible range for an average human is 200 Hz to 200,000 Hz. 2. Sounds with frequencies below 20 Hz are called infrasound. 3. Rhinoceroses communicate using infrasound. Which of the statements given above are correct?

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Ordinary sound waves are unsuitable for detecting flaws in metal blocks primarily because:

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Keep practising Chapter 5: Sound

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