Syllabus covered in the MSVgo app

Download MSVgo app now!

Chapter 7 – Sound

The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:

Introduction

You must already know that sound is defined as a form of energy like light, heat, kinetic energy, potential energy, etc. It is the energy that is transferred from one molecule to another, creating a sensation to the ear, which is called hearing. Since sound is a form of energy, it is neither created nor destroyed. It just gets changed from one form to another. Just like, you speak and your friend hears what you said.

The production of sound happens in different ways. Some of them are listed below:

  • In simple terms, we can say that sound is produced whenever any object creates vibrations. 
  • Vibration or sounds can be caused due to the motion of objects and materials.
  • The rapid to-and-fro motion of any object is called oscillation, and this produces sound. Sound can be monotone or can consist of multiple frequencies.

For example, when a rubber band is plucked, it creates a vibration, resulting in the production of sound.

Also, when a tuning fork is struck to a rubber pad, it vibrates, creating a sonorous sound.

After understanding what sound is and how it is produced, the next concept we need to understand is the propagation of sound. 

  • The phenomenon of sound travelling from one object to another is called the propagation of sound. 
  • Sound always needs a medium to travel, due to which, whenever sound is created, it starts to vibrate the particles around it. 
  • When sound leaves a source, it starts to vibrate the nearest particles in the medium and keeps following this process until it reaches a listener. 
  • When any vibrating object produces a disturbance, it gets carried through the medium. However, in the entire process, none of the particles moves forward. They just create a chain of vibration by disturbing the particles in front of them.

Reflection of light occurs as the waves encounter a reflecting surface or its borders, not absorbing the radiation energy while the waves bounce back from the body. When light rays reflect a body, they travel from one transparent medium to another or move through a medium with a frequently altered composition. According to the law of reflection:

  • The incident ray, the reflected ray and the normal to the surface at the point of incidence all lie in the same plane.
  • The angle of incidence is equal to the angle of reflection.

Till now, you would have understood that sound is a wave formed due to a disturbance in the particles. Now, we need to get a better understanding of sound as a longitudinal wave and the types of waves.

Based on the direction of propagation, a wave can be categorised into two types—transverse and longitudinal waves. 

  •  Transverse waves
    The transverse waves are those waves in which the particles of the medium resonate to-and-fro, perpendicular to the wave’s direction. The best example of transverse waves is light waves.
  • Longitudinal waves
    This is the kind of wave in which the particles resonate to-and-fro in the same direction as that of the wave. Sound waves are an example of longitudinal waves.

Here are a few characteristics of sound waves:

  • Amplitude
    When a wave disturbance is plotted on a graph, the amplitude is the height of the crest and trough. The amplitude of any sound wave is defined by how high or low the parabola is formed. Amplitude is denoted by ‘A’, and the SI unit of amplitude is metre. Amplitude is also directly proportional to the loudness of a wave. This means the greater the amplitude higher will be the loudness. Amplitude highly depends on the force by which the particles vibrate, and, therefore, softness, loudness and amplitude are related to one another.
  • Wavelength
    Wavelength is defined as the distance between two consecutive crests or troughs. It is denoted by λ (lambda), and the SI unit of wavelength is metre. Wavelength is also considered as the distance at which the graph is repeated.
  • Frequency
    The frequency of the sound wave is defined as the number of vibrations that are completed by any particle in one second.Frequency = Number of oscillations/Total TimeEvery sound wave has compressions and rarefactions, and the frequency of any sound wave can be determined by simply calculating the number of compressions or rarefactions in one second. The SI unit of frequency is Hertz (Hz).
  • Time period
    The time taken by any particle to complete one oscillation is called the time period. It is represented by ‘T’, and its SI unit is seconds.Time period and frequency are related to each other because the time period is the number of oscillations in one second and frequency is the total number of compressions and rarefactions in one second.
  • Pitch
    Pitch and frequency are related to each other. Pitch is defined as the sensation of the frequency of an emitted sound. The pitch of any sound is directly proportional to the frequency of vibrations. A high-pitch sound has a higher frequency of vibration and is known as a shrill sound, whereas a low-pitch sound is called a heavy sound. This is measured in decibels. The unit of loudness is also measured in decibels.

This is a crucial chapter for students because there are several concepts that students have to use even in their college. The chapter holds a good score in JEE and other competitive examinations. Students who wish to take science as their stream in Class 11th should concentrate well on this chapter and learn all the fundamentals.

  1. Sound travels faster through which state of matter?
    Sound travels faster through solids as compared to other states of matter.
  2. What is the SI unit of frequency?
    The SI unit of frequency is Hertz.
  3. Can sound travel in a vacuum? If not, then why.
    Sound cannot travel in a vacuum because it always needs a medium for travelling.

MSVgo is an excellent learning platform that allows students to learn various concepts in a better way. It is a very innovative and engaging video platform that gives you all the information and knowledge about the chapters. You can easily download it from the iOS App Store or Google Play Store here.

High School Physics

  • Alternating Current
  • Atoms
  • Communication Systems
  • Current Electricity
  • Dual nature of Radiation and Matter
  • Electric Charges and Fields
  • Electricity
  • Electromagnetic Induction
  • Electromagnetic Waves
  • Electron Beams and Radioactivity
  • Electrons and Photons
  • Electrostatic Potential and Capacitance
  • Fluid Pressure
  • Force and Acceleration
  • Force And Laws Of Motion
  • Gravitation
  • Internal Energy
  • Kinetic Theory
  • Law of motion
  • Light – Reflection And Refraction
  • Magnetic Effects Of Electric Current
  • Magnetism and Matter
  • Management Of Natural Resources
  • Mechanical properties of Fluids
  • Mechanical properties of Solids
  • Motion
  • Motion in a plane
  • Motion in a straight line
  • Moving Charges and Magnetism
  • Nuclear Energy
  • Nuclei
  • Oscillations
  • Our Environment
  • Paths of Heat
  • Physical world
  • Ray optics and optical instruments
  • Semiconductor Devices
  • Semiconductor Electronics: Materials, Devices and Simple Circuits
  • Simple Machines
  • Sound
  • Sources Of Energy
  • Specific and Latent Heats
  • Spherical Mirrors
  • Static Electricity
  • Systems of Particles and Rotational motion
  • Thermal properties of matter
  • Thermodynamics
  • Units and Measurement
  • Vectors, Scalar Quantities and Elementary Calculus
  • Wave Optics
  • Waves
  • Work, Power and Energy

High School Chemistry

  • Acids, Bases and Salts
  • Alcohols, Phenols and Ethers
  • Aldehydes, Ketones and Carboxylic Acids
  • Aliphatic and Aromatic Hydrocarbons
  • Alkyl and Aryl Halides
  • Amines
  • Analytical Chemistry 
  • Atomic Structure
  • Atoms And Molecules
  • Basic concepts of Chemistry
  • Biomolecules
  • Carbon And Its Compounds
  • Carboxylic acids and Acid Derivatives
  • Chemical Bonding and Molecular Structures
  • Chemical Energetics
  • Chemical Equilibria
  • Chemical Kinetics
  • Chemical Reactions And Equations
  • Chemical Reactions and Their Mechanisms
  • Chemistry in Everyday Life
  • Chemistry of p-Block elements
  • Chemistry of Transition and Inner Transition
  • Classification of Elements
  • Coordination Compounds
  • Cyanide, Isocyanide, Nitro compounds and Amines
  • Electrochemistry
  • Electrolysis
  • Elements, Compounds and Mixtures
  • Environmental Chemistry
  • Equilibrium
  • Ethers and Carbonyl compounds
  • Haloalkanes and Haloarenes
  • Hydrocarbons
  • Hydrogen
  • Ideal solutions
  • Introduction to Organic Chemistry
  • Ionic equilibria
  • Matter
  • Matter Around Us
  • Matter In Our Surroundings
  • Metallurgy
  • Metals And Non-Metals
  • Mole Concept and Stoichiometry
  • Natural Resources
  • Organic Chemistry – Basic Principles
  • Periodic Classification of Elements
  • Physical and Chemical Changes
  • Physical and Chemical Properties of Water
  • Polymers
  • Preparation, Properties and Uses of Compounds
  • Principles and Processes of Isolation of Elements
  • Redox Reactions
  • Relative Molecular Mass and Mole
  • States of Matter
  • Structure Of The Atom
  • Study of Compounds
  • Study of Gas Laws
  • Study of Representative Elements
  • Surface Chemistry
  • The d-block and f-block elements
  • The Gaseous State
  • The p-Block Elements
  • The Periodic Table
  • The s-Block Elements
  • The Solid State
  • Thermodynamics

High School Biology

  • Absorption and Movement of Water in Plants
  • Adolescent Issues
  • Anatomy of Flowering Plants
  • Animal Kingdom
  • Bacteria and Fungi-Friends and Foe
  • Biodiversity and Conservation
  • Biofertilizers
  • Biological Classification
  • Biomedical Engineering
  • Biomolecules
  • Biotechnology and its Applications
  • Biotic Community
  • Body Fluids and Circulation
  • Breathing and Exchange of Gases
  • Cell – Unit of Life
  • Cell Cycle and Cell Division
  • Cell Division and Structure of Chromosomes
  • Cell Reproduction
  • Cellular Respiration
  • Chemical Coordination and Integration
  • Circulation
  • Control And Coordination
  • Crop Improvement
  • Digestion and Absorption
  • Diversity In Living Organisms
  • Ecosystem
  • Environmental Issues
  • Excretory Products and their Elimination
  • Flowering Plants
  • Genes and Chromosomes
  • Health and Diseases
  • Health and Its Significance
  • Heredity And Evolution
  • Heredity and Variation
  • How Do Organisms Reproduce?
  • Human Diseases
  • Human Eye And Colourful World
  • Human Health and Disease
  • Human Population
  • Human Reproduction
  • Hygiene
  • Improvement In Food Resources
  • Integumentary System- Skin
  • Kingdom Fungi
  • Kingdom Monera
  • Kingdom Protista
  • Life Processes
  • Locomotion and Movement
  • Microbes in Human Welfare
  • Mineral Nutrition
  • Molecular Basis of Inheritance
  • Morphology of Flowering Plants
  • Neural Control And Coordination
  • Nutrition in Human Beings
  • Organism and Population
  • Photosynthesis
  • Photosynthesis in Higher Plants
  • Plant Growth and Development
  • Plant Kingdom
  • Pollination and Fertilization
  • Pollution; Sources and its effects
  • Principles of Inheritance and Variation
  • Reproduction and Development in Angiosperms
  • Reproduction in Organisms
  • Reproductive Health
  • Respiration in Human Beings
  • Respiration in Plants
  • Respiratory System
  • Sexual Reproduction in Flowering Plants
  • Strategies for Enhancement in Food Production
  • Structural Organisation in Animals
  • Structural Organisation of the Cell
  • The Endocrine System
  • The Fundamental Unit Of Life
  • The Living World
  • The Nervous System and Sense Organs
  • Tissues
  • Transpiration
  • Transport in Plants

High School Math

  • Algebra – Arithmatic Progressions
  • Algebra – Complex Numbers and Quadratic Equations
  • Algebra – Linear Inequalities
  • Algebra – Pair of Linear Equations in Two Variables
  • Algebra – Polynomials
  • Algebra – Principle of Mathematical Induction
  • Algebra – Quadratic Equations
  • Binomial Theorem
  • Calculus – Applications of Derivatives
  • Calculus – Applications of the Integrals
  • Calculus – Continuity and Differentiability
  • Calculus – Differential Equations
  • Calculus – Integrals
  • Geometry – Area
  • Geometry – Circles
  • Geometry – Conic Sections
  • Geometry – Constructions
  • Geometry – Introduction to Euclid’s Geometry
  • Geometry – Three-dimensional Geometry
  • Geometry – Lines and Angles
  • Geometry – Quadrilaterals
  • Geometry – Straight Lines
  • Geometry – Triangles
  • Linear Programming
  • Matrices and Determinants
  • Mensuration – Areas
  • Mensuration – Surface Areas and Volumes
  • Number Systems
  • Number Systems – Real Numbers
  • Permutations and Combinations
  • Probability
  • Sequence and Series
  • Sets and Functions
  • Statistics 
  • Trignometry – Height and Distance
  • Trignometry – Identities
  • Trignometry – Introduction

Middle School Science

  • Acids, Bases And Salts
  • Air and Its Constituents
  • Basic Biology
  • Body Movements
  • Carbon and Its Compounds
  • Cell – Structure And Functions
  • Changes Around Us
  • Chemical Effects Of Electric Current
  • Chemistry in Your Life
  • Coal And Petroleum
  • Combustion And Flame
  • Components Of Food
  • Conservation Of Plants And Animals
  • Crop Production And Management
  • Electric Current And Its Effects
  • Electricity And Circuits
  • Elements and Compounds
  • Fibre To Fabric
  • Food production and management
  • Force And Pressure
  • Forests: Our Lifeline
  • Friction
  • Fun With Magnets
  • Garbage In, Garbage Out
  • Getting To Know Plants
  • Health and Hygiene
  • Heat
  • Hydrogen
  • Life Processes: Nutrition in Animals and Plants
  • Light, Shadows And Reflections
  • Materials: Metals And Non-Metals
  • Matter and Its States
  • Metals and Non-metals
  • Micro Organisms: Friend And Foe
  • Motion And Measurement Of Distances
  • Motion And Time
  • Nutrition In Animals
  • Nutrition In Plants
  • Organization in Living Things
  • Our Environment
  • Physical And Chemical Changes
  • Pollution and conservation
  • Pollution Of Air And Water
  • Reaching The Age Of Adolescence
  • Reproduction In Animals
  • Reproduction In Plants
  • Respiration In Organisms
  • Rocks and Minerals
  • Separation Of Substances
  • Simple Machines
  • Soil
  • Some Natural Phenomena
  • Sorting Materials Into Groups
  • Sound
  • Stars And The Solar System
  • Structure of Atom
  • Synthetic Fibers And Plastics
  • The Living Organisms And Their Surroundings
  • Transfer of Heat
  • Transformation of Substances
  • Transportation In Animals And Plants
  • Universe
  • Waste-water Story
  • Water: A Precious Resource
  • Weather, Climate And Adaptations Of Animals To Climate
  • Winds, Storms And Cyclones

Middle School Math

  • Addition
  • Area and Its Boundary
  • Boxes and Sketches
  • Data Handling
  • Fun With Numbers
  • Heavy and Light
  • How Many
  • Long And Short
  • Mapping
  • Measurement
  • Money
  • Multiplication and Factors
  • Multiply and Divide
  • Numbers
  • Parts and Wholes
  • Pattern Recognition
  • Patterns
  • Play With Patterns
  • Rupees And Paise
  • Shapes And Angles
  • Shapes And Designs
  • Shapes and Space
  • Similarity
  • Smart Charts
  • Squares
  • Subtraction
  • Tables And Shares
  • Tenths and Hundredths
  • Time
Please switch to portrait mode
for the best experience.
Click to open Popup