NCERT Exemplar Class 9 Science Chapter 12 Solutions: Sound

NCERT Exemplar Class 9 Science Solution for Chapter 12 ‘Sound’ will help you in learning all the fundamentals of the chapter quickly. We hear sound every day from different sources like machines, humans, vehicles, radios, bells, etc. But, do you have any idea about what sound is? Do you know that it is a form of energy? Well, you will learn everything about sound in this chapter of NCERT Class 9 Science Exemplar with topics like sound and its production, how sound travel, types of sound waves and compression.

Chapter 12 of NCERT Exemplar Class 9 Science has 20 Exemplar problems that are divided into 3 sections – multiple-choice questions, short answer questions, and long answer questions. The questions in NCERT Exemplar Class 9 Science Chapter 12 are designed as per the latest CBSE exam pattern. The main benefit of practising these different types of NCERT Exemplar problems is that you will be able to prepare well for the exams. 

Instasolv works hard to help you score the best grades in their examination. Professionals at instasolv guarantee to give clear and easy to understand solutions to every question. The main aim is to help you solve all your queries related to the chapter and your boost confidence. 

Important Topics for NCERT Exemplar Class 9 Science Solutions Chapter 12: Sound

We hear various sounds every day. A sound is a form of energy that produces hearing sensation in our ears. The NCERT Exemplar Class 9 Science Problems and  Solutions for Chapter 12 discuss the study of the energy of sound followed by the topics covered in the chapter.

Production of sound

  • Sound is produced by vibrating objects. For eg- human voice is produced due to vibrations in vocal cords. 
  • Vibration is a kind of rapid to and fro motion of an object.

Propagation of sound

  • The matter of the subject through which the sound travels is called a medium be it solid liquid or gas. 
  • Sound travels through a medium from the point of generation to the listener. 
  • The whole concept of sound travelling through a medium is explained in the chapter with the help of interesting diagrams or figures.
  • Some of the concepts discussed under this topic are sound needs a medium to travel, sound waves are longitudinal waves, and characteristics of a sound wave.

Reflection of sound

  • Just like a rubber ball bounces from the wall, similarly sound bounces off a solid or a liquid.
  • Sound reflects on solid or liquid just like light reflects. An obstacle of large size which may be polished or rough is needed for the reflection of sound waves.
  • This concept is subdivided into various important concepts of sound that you will study in the chapter. For eg- echo, reverberation, multiple reflections of sound.

Applications of ultrasound

  • Ultrasounds are the high-frequency waves and are able to travel along well-defined paths even in the presence of obstacles.
  • Ultrasounds are generally used in the industry for medical use. Other uses of ultrasounds are to detect cracks and flaws in the metal box, clean parts located in the hard to reach places, etc.
  • Various diagrams are also shown in the chapter to define the ultrasonic waves and explain the core of the concept.

Structure of the human ear

  • The human ear is an extremely sensitive device. The concept is a thorough explanation of the structure of a human ear.
  • Ear allows us to create pressure variations in the air with audible frequencies into electronic signals that travel to the brain through the auditory nerve.
  • In the chapter, the concept of the human ear is explained with the help of a fully labelled diagram of auditory parts of the human ear.

Exercise Discussion of NCERT Exemplar Class 9 Science Solutions Chapter 12: Sound

  • The chapter consists of a total of 20 questions that check your understanding of different topics of the chapter. The first set of exercises contains 9 multiple-choice questions on topics like what is a sound, what do you use in sonar, etc. 
  • The second set consists of 8 short answer questions. These questions are a combination of graphical questions, giving a reason to the question or solving the numerical. You will be asked if the given graph shows the displacement versus time relation for a disturbance travelling with a velocity of 1500m. You will need to calculate the wavelength of the disturbance.
  • The set contains 3 long answer questions you will have to represent the situation in the form of graphs and diagrams. For instance, two cases will be given in the question and you will be asked to represent the situation graphically by two separate diagrams.

Benefits of NCERT Exemplar Class 9 Science Solutions Chapter 12: Sound by Instasolv

  • NCERT Exemplar Class 9 Science problems and solutions for Chapter 12 are provided by the team of Instasolv in a very simplified language.
  • Our subject matter experts possess years of experience. The team strives together to provide you with the best learning experience in the field of science. 
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