Lakhmir Singh Physics Class 9 Solutions Sound (Chapter 5)

Lakhmir Singh Physics Class 9 Solutions Sound Chapter 5 are going to help you learn all the fundamentals of the chapter quickly. We all hear sounds every day from different sources like bells, machines, humans, vehicles, television, radios, etc. Do you know that sound is a form of energy? Sound is something that produces a sensation in the ears. In this chapter, you will know if you can produce sound without applying energy, or which energy is required to produce sound.

Lakhmir Singh Solutions for CBSE Class 9 Chapter 5 have around 9 exercises with a total of 199 questions. The questions are designed as per the latest exam pattern. The benefits of choosing Lakhmir Singh Solutions is that you will be able to practice questions from the basic to advanced level. These solutions will make your course content easy as we have created high-quality answers for you.

Instasolv has the best Physics subject experts who dedicatedly work to solve the doubts of the students. So, you can easily access all the solutions by sitting at home. Exam preparation is now super easy for you.

Important Topics for Lakhmir Singh and Manjit Kaur Solutions for Class 9 Physics Chapter 5

Sound and its production 

At first, chapter 5 explains what is sound and how sound is produced using different activities. Do you know that sound needs a medium to travel? If not, then read the chapter thoroughly. Then you will be able to answer all the questions given below. 

  • What are the sound waves?
  • How sound is produced?
  • Does sound travel?
  • What sources does sound use to travel?
  • You will learn about oscillations and their detailed concepts. 
  • What is the wavelength and what causes it?
  • How time period and frequency affect the sound?
  • On what factors does the speed of sound matter?
  • Laws of Reflection of sound and its impact 
  • What are all the properties of sound that affect it?
  • What are reverberation and compression?
  • All about the intensity of sound 
  • Appropriate Audible range of hearing in human beings and animals
  • Types of sound waves

Numerical Problems based on Sound 

The sound chapter has many numerical questions that ask you to find velocity, speed, wavelength, distance, and amplitude, etc. Let’s solve an example here. 

Question: A person clapped his hands near the cliff and he heard the echo of it after 5 seconds. Find the distance of the cliff from the person if the speed of the sound, v is taken as 346 ms-1?

Solution: Given,

Speed of sound, v = 346ms-1

Time taken for hearing the echo= 5 seconds


Distance travelled by the sound = v x t = 346ms-1x 5s = 1730m

In 5s, the sound has to travel double the distance between the person and the cliff. Thus, the distance between the cliff and the person= 1730m/2 = 865m. 

Exercise Wise discussion of Lakhmir Singh Physics Class 9 Solutions Sound Chapter 5

Exercise 1 Page 185

This exercise has around 30 questions in which you need to answer about how sound travels, in which medium sound travels faster, type of wave produced by sound, etc. 

Exercise 2 Page 186

This exercise set has around 29 questions. These questions vary from short answer questions to numerical on sound. These questions are on sound, frequency, and some other situations which you need to answer according to the question. Also, you should know every topic of the chapter in detail as the questions even ask you to differentiate between two terms. 

There are around 7 more exercises in this chapter. These exercises deal with the different topics of the chapter like frequency, explanation on different types of waves, numerical, etc. Each and every set of exercise is essential as every exercise set has a variety of questions which are necessary for you to understand. 

Benefits of Lakhmir Singh Solutions for Class 9 Physics Chapter 5 by Instasolv

Lakhmir Singh and Manjit Kaur Science Books are the perfect study material that will help you in clearing the basic concepts of science in class 9. Also, you will be able to practice questions in a proper manner so that you can prepare for your exams perfectly. Lakhmir Singh Physics Class 9 Solutions Sound Chapter 5 by Instasolv are perfect in all ways. Instasolv team has expertise in the field of physics that they render through solutions to all the questions. The main agenda of the team is to make the course content easy for you.