With reference to the 'Quality' or 'Timbre' of sound, consider the following statements: 1. It enables us to distinguish one sound from another having the same pitch and loudness. 2. A sound of a single frequency is called a note. 3. A sound produced by a mixture of several frequencies is called a tone. Which of the statements given above is/are correct?

The correct option is (a). Explanation Sound waves are characterized by three fundamental properties: loudness, pitch, and quality (or timbre). These characteristics determine how the ear perceives sound based on amplitude, frequency, and waveform complexity. Statement-wise Analysis: - Statement 1 is Correct: Quality or timbre is the characteristic of sound that enables us to distinguish between two sounds having the same pitch and loudness. This distinction arises because different sources (like a violin and a flute) produce different waveforms due to the presence and relative strength of overtones (harmonics). - Statement 2 is Incorrect: A sound composed of a single frequency is technically defined as a tone. Pure tones are typically produced by devices like tuning forks. - Statement 3 is Incorrect: A sound produced by a mixture of several frequencies is called a note. Musical instruments generally produce notes, which are pleasant to the ear and consist of a fundamental frequency combined with various harmonics. Key Takeaway: A tone refers to a single frequency, while a note is a composite sound of multiple frequencies. Timbre is the unique quality that distinguishes sounds of identical pitch and loudness.

NCERT Class 9 Science — Chapter 5: Sound

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With reference to the 'Quality' or 'Timbre' of sound, consider the following statements:

It enables us to distinguish one sound from another having the same pitch and loudness.
A sound of a single frequency is called a note.
A sound produced by a mixture of several frequencies is called a tone.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

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

Did you get this right?

Solution

The correct option is (a).

Explanation

Sound waves are characterized by three fundamental properties: loudness, pitch, and quality (or timbre). These characteristics determine how the ear perceives sound based on amplitude, frequency, and waveform complexity.

Statement-wise Analysis:

Statement 1 is Correct: Quality or timbre is the characteristic of sound that enables us to distinguish between two sounds having the same pitch and loudness. This distinction arises because different sources (like a violin and a flute) produce different waveforms due to the presence and relative strength of overtones (harmonics).
Statement 2 is Incorrect: A sound composed of a single frequency is technically defined as a tone. Pure tones are typically produced by devices like tuning forks.
Statement 3 is Incorrect: A sound produced by a mixture of several frequencies is called a note. Musical instruments generally produce notes, which are pleasant to the ear and consist of a fundamental frequency combined with various harmonics.

Key Takeaway:

A tone refers to a single frequency, while a note is a composite sound of multiple frequencies. Timbre is the unique quality that distinguishes sounds of identical pitch and loudness.

Your note

More from Chapter 5: Sound

Consider the following statements regarding the propagation of sound: 1. The disturbance created by a source travels through the medium to the listener. 2. Sound waves are characterized as non-mechanical waves. 3. A material medium is mandatory for the transmission of sound. Which of the statements given above are correct?

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With reference to the characteristics of a sound wave, consider the following statements: 1. The distance between two consecutive compressions is called the wavelength. 2. The time taken for one complete oscillation is called the frequency. 3. The SI unit of frequency is Hertz. Which of the statements given above are correct?

medium

Consider the following statements regarding Ultrasound: 1. It refers to sounds with frequencies higher than 20 kHz. 2. Ultrasound waves scatter immediately when they encounter obstacles. 3. Ultrasound is incapable of penetrating metal blocks to detect flaws. Which of the statements given above is/are correct?

easy

The cleaning action of an ultrasonic cleaner is primarily achieved through:

medium

With reference to medical applications of sound, consider the following statements: 1. Echocardiography uses ultrasonic waves to form an image of the heart. 2. Ultrasonography uses X-rays to detect stones in the gall bladder. 3. Ultrasound can be used to break kidney stones into fine grains. Which of the statements given above are correct?

medium

Keep practising Chapter 5: Sound

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The correct option is (a).

Explanation

Statement-wise Analysis:

Statement 1 is Correct: Quality or timbre is the characteristic of sound that enables us to distinguish between two sounds having the same pitch and loudness. This distinction arises because different sources (like a violin and a flute) produce different waveforms due to the presence and relative strength of overtones (harmonics).
Statement 2 is Incorrect: A sound composed of a single frequency is technically defined as a tone. Pure tones are typically produced by devices like tuning forks.
Statement 3 is Incorrect: A sound produced by a mixture of several frequencies is called a note. Musical instruments generally produce notes, which are pleasant to the ear and consist of a fundamental frequency combined with various harmonics.

Key Takeaway:

A tone refers to a single frequency, while a note is a composite sound of multiple frequencies. Timbre is the unique quality that distinguishes sounds of identical pitch and loudness.