NCERT Solutions for Class 9 Science Chapter 12: Sound

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The NCERT Solutions for Class 9 Science Chapter 12 Sound are provided in this article below. Some of the important concepts of Class 9 Science Chapter 12 Sound are:

Difference Between Echo and Reverberation
Structure of Human Ear
Sonar

Download: NCERT Solutions for Class 9 Science Chapter 4 pdf

NCERT Solutions for Class 9 Science Chapter 3

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NCERT Solution

Important Topics for Class 9 Science Chapter 12 Sound

A sound is a vibration that propagates through a medium in the form of a mechanical wave. The medium in which it propagates can either be a solid, a liquid or a gas. Sound travels fastest in solids, relatively slower in liquids and slowest in gases. Sound moves through a medium by alternately expanding and contracting the parts of the medium which it is traveling through.

Diference Between Echo and Reverberation

Echo occurs due to the spontaneous reflection of sound from various surfaces, including walls, furniture, and other similar objects. However, Reverberation porpagates via air due to multiple reflections of sound waves from different surfaces like walls, furniture and more.’

Example: The formation of_______ is found to occur when the reflecting surface is 17m.

Echoes
Noise
Sound
Reverberation

Solution: Option 1 is the correct answer as because echoes are known to cause when certain reflecting surfaces are at a distance greater than 17m and more.

Structure of Human Ear

Human ear is known to include three parts, namely the outer ear, middle ear and inner ear. Ideally, the ear canal situated upon the outer ear is found separated from the tympanic cavity located in the middle ear by the eardrum.

Example: Highlight the function of hearing.

Solution: Hearing is the basic function of the human ear. It basically works towards identiffying and interpreting sounds in our surroundings. The ears further helps to send electrical signals to the brain, assisting the brain to perceive and comprehend the sound. The sequential process of identifying, analysing and decoding sound waves is known as hearing.

Sonar

Sonar is an abbreviation of “Sound Navigation and Ranging.” Sonar is basically a navigation system which identifies and uses acoustic signals to recognize distant underwater communications.

Sonar technologies can be further classified into two segments:

Active Sonar
Passive Sonar

Also Read:

Chapter Related Links
Intensity of Sound	Frequency and Wavelength	Unit of Vibration
Sound Important Questions	Ear Ossicles	Inaudible and Audible Sound
Sound Waves	Reflection of Waves	Loudness of Sound

Also Check:

Important Science Study Guides
Physics Constants	Difference between in chemistry	Difference between in biology
Named Reactions	Difference between in physics	Periodic Table

CBSE X Related Questions

1.
Assertion (A): Carbon shares its valence electrons with other atoms of carbon or with atoms of other elements.
Reason (R): The shared electrons belong to the outermost shells of both the atoms and lead to both atoms attaining the noble gas configuration.

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
Assertion (A) is true, but Reason (R) is false.
Assertion (A) is false, but Reason (R) is true.

View Solution

2.
Identify the correct statement for spirogyra, leishmania and hydra

they reproduce sexually.
they are unicellular.
they are multicellular.
they reproduce asexually.

View Solution

3.
Which of the following group is not 'biodegradable'?

Vegetable peels, dead leaves, paper
Cow dung, leather bag, water
Polythene bag, rubber band, ball pen
Paper, fruits, bones

View Solution

4.
Assertion (A): Ozone at higher levels of atmosphere is a product of UV radiation acting on oxygen molecule.
Reason (R): The higher energy of UV splits apart some molecular \( O_2 \).

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
Assertion (A) is true, but Reason (R) is false.
Assertion (A) is false, but Reason (R) is true.

View Solution

5.
Assertion : Bacteria produced as a result of asexual reproduction would be similar. Reason (R): There would be only minor differences between the bacteria generated due to small inaccuracies in DNA replication.

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
Assertion (A) is true, but Reason (R) is false.
Assertion (A) is false, but Reason (R) is true.

View Solution

6.
Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
Assertion (A) is true, but Reason (R) is false.
Assertion (A) is false, but Reason (R) is true.

View Solution

NCERT Solutions for Class 9 Science Chapter 12: Sound

NCERT Solutions for Class 9 Science Chapter 3

Important Topics for Class 9 Science Chapter 12 Sound

Diference Between Echo and Reverberation

Structure of Human Ear

Sonar

CBSE X Related Questions

1.
Assertion (A): Carbon shares its valence electrons with other atoms of carbon or with atoms of other elements.
Reason (R): The shared electrons belong to the outermost shells of both the atoms and lead to both atoms attaining the noble gas configuration.

2.
Identify the correct statement for spirogyra, leishmania and hydra

3.
Which of the following group is not 'biodegradable'?

4.
Assertion (A): Ozone at higher levels of atmosphere is a product of UV radiation acting on oxygen molecule.
Reason (R): The higher energy of UV splits apart some molecular \( O_2 \).

5.
Assertion : Bacteria produced as a result of asexual reproduction would be similar. Reason (R): There would be only minor differences between the bacteria generated due to small inaccuracies in DNA replication.

6.
Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.

Similar Science Concepts

Comments

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NCERT Solutions for Class 9 Science Chapter 12: Sound

NCERT Solutions for Class 9 Science Chapter 3

Important Topics for Class 9 Science Chapter 12 Sound

Diference Between Echo and Reverberation

Structure of Human Ear

Sonar

CBSE X Related Questions

1.Assertion (A): Carbon shares its valence electrons with other atoms of carbon or with atoms of other elements. Reason (R): The shared electrons belong to the outermost shells of both the atoms and lead to both atoms attaining the noble gas configuration.

2.Identify the correct statement for spirogyra, leishmania and hydra

3.Which of the following group is not 'biodegradable'?

4.Assertion (A): Ozone at higher levels of atmosphere is a product of UV radiation acting on oxygen molecule. Reason (R): The higher energy of UV splits apart some molecular \( O_2 \).

5.Assertion : Bacteria produced as a result of asexual reproduction would be similar. Reason (R): There would be only minor differences between the bacteria generated due to small inaccuracies in DNA replication.

6.Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.

Similar Science Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

1.
Assertion (A): Carbon shares its valence electrons with other atoms of carbon or with atoms of other elements.
Reason (R): The shared electrons belong to the outermost shells of both the atoms and lead to both atoms attaining the noble gas configuration.

2.
Identify the correct statement for spirogyra, leishmania and hydra

3.
Which of the following group is not 'biodegradable'?

4.
Assertion (A): Ozone at higher levels of atmosphere is a product of UV radiation acting on oxygen molecule.
Reason (R): The higher energy of UV splits apart some molecular \( O_2 \).

5.
Assertion : Bacteria produced as a result of asexual reproduction would be similar. Reason (R): There would be only minor differences between the bacteria generated due to small inaccuracies in DNA replication.

6.
Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.