CBSE Physics Class 8 Notes Last Updated : 18 Mar, 2023 Comments Improve Suggest changes Like Article Like Report GeeksforGeeks came up with a unique outlook to School Learning by providing CBSE Class 8 Physics notes. Since science is an integral subject of School Learning so is Physics too. Physics is one of the disciplines that most students grow up studying. This subject, in general, offers an understanding of how the fundamental elements of our daily lives function and perform. Therefore, GeeksforGeeks Class 8 Physics Notes ensures that you study everything in accordance with your NCERT textbook, core books, or reference books. The following chapter-wise CBSE Class 8 Physics notes consist of 7 chapters including Force and Pressure, Sound, Light, etc which are further equipped with various concepts, everyday life examples, and numericals on the same, in order to understand and solve the problems in a better way. Chapter 1: Force and Pressure The first chapter of Physics in the Science curriculum of Class 8 is Force and Pressure. Force is simply the push and pulls upon an object while Pressure is defined as the force applied per unit area of the object. Both the terms Force and Pressure are the basic building blocks of mechanics (a part of Physics). This chapter consists of two parts Force and Pressure respectively, Force includes basic concepts, types, properties/characteristics of forces, Friction and its different types, etc. While, the section on Pressure comprises Basic concepts, Types of Pressure and Buoyancy, etc which are explained in the articles listed below: What is Force?Push and Pull ForceInteraction of ForcesTypes of ForcesExploring ForcesContact and Non Contact ForcesChange in State of MotionFriction: A Necessary EvilFactors Affecting FrictionTypes of FrictionStatic and Kinetic FrictionLimiting FrictionSliding FrictionFluid FrictionIncreasing and Reducing FrictionWhat is Pressure?Types of PressureFluid PressureAtmospheric PressureHydrostatic PressureBuoyancyChapter 2: Sound Sound is the second chapter of Physics in the Science curriculum of Class 8. Sound is something that can be heard from anything like Television, aeroplane, etc. Scientifically, Sound can be defined as an energy form that propagates in the form of waves and is produced by vibrations. The topics covered in this chapter helps to understand, the basic concept of Sound, Production, and propagation of Sound, Characteristics of Sound waves (like Amplitude, Time period, Frequency, Pitch, and Loudness), Types of Sounds (Audible and Inaudible Sounds) and about the Pollution caused by excessive sound that is Noise pollution. All such topics are thoroughly explained under the following headings as listed below: Sound Produced by a Vibrating BodyHow is Sound Produced by Humans?Sound Needs a Medium for PropagationHow do we hear?Amplitude, Time Period, and Frequency of a VibrationPitch and LoudnessAudible and Inaudible SoundsNoise PollutionChapter 3: Chemical Effects of Electric Current The third chapter of Physics in the Science textbook comes up is called Chemical Effects of Electric Current. Electric Current is the rate of the flow of electrons or charges in a conductor. Therefore, the passage of electric current through a conducting solution results in chemical reactions. This chapter builds a basic idea of electricity, which will be studied in later classes. As this chapter helps to develop a general idea, so we will learn about electroplating and the chemical changes that occur when electricity flows through the liquid and its applications. The topic discussed are listed below: Good Conductors and Poor Conductors of ElectricityDo Liquids Conduct Electricity?Bases and Salts are Good ConductorsChemical Effects of Electric CurrentElectrolysis of WaterWhat is Electroplating?Chapter 4: Some Natural Phenomena Some Natural Phenomena is the fourth chapter of Class 8 Physics. As the name of the chapter says, Some Natural Phenomena, therefore, it explains some naturally causing phenomena like lightning, earthquake which are destructive to some extent. Thus, the topics covered in this chapter come up with the basic idea of lightning and Earthquakes, the destruction caused by them, how they occur? and measures to be taken during them. These concepts are discussed in the following articles: What is Lightning?How Lightning Works?Electric ChargeElectroscopeWhat is Earthing?Earthquake – Definition, Causes, Effects, ProtectionWhat causes an Earthquake?Chapter 5: Light The fifth chapter in the Class 8 Physics syllabus is Light. Light is a form of energy that enables us to see our surroundings when it gets reflected from objects around us. Light is emitted from a source such as the Sun. The term usually refers to visible light, which is visible to the human eye and is responsible for the sense of sight. This chapter helps to develop the general and the basic concept of Optics (a branch of Physics). According to the CBSE Class 8 Science Curriculum, here we have covered topics like the concept of Reflection, Laws of Reflection, Types of Reflection, Structure, and Working of the Human Eye, Dispersion of Light, etc. are discussed in the following articles listed below: Reflection of LightLaws of ReflectionRegular and Diffused ReflectionMultiple Reflections of LightDispersion of LightHuman EyeBraille SystemChapter 6: Stars and the Solar System The last chapter of CBSE Class 8 Physics is Stars and the Solar System that leads one to go to infinity and beyond. Topics covered are celestial objects, Sun, comets, astronomy, planets, meteors, and meteorites, moon, satellites, meteor shower, stars, Astronomy in ancient India, artificial satellites, constellation, Mangalyaan which are discussed in the following articles listed below: What is a Star? Formation, Life Span, ConstellationsThe Moon – Facts, Phases, Surface, EclipseArtificial Satellites Comment More infoAdvertise with us Next Article Force A abhishek1 Follow Improve Article Tags : School Learning Class 8 Physics Physics-Class-8 Tutorials +1 More Similar Reads CBSE Physics Class 8 Notes GeeksforGeeks came up with a unique outlook to School Learning by providing CBSE Class 8 Physics notes. Since science is an integral subject of School Learning so is Physics too. Physics is one of the disciplines that most students grow up studying. This subject, in general, offers an understanding 5 min read Chapter 1: Force and PressureForceForce is defined as an external cause that a body experiences as a result of interacting with another body. Whenever two objects interact, a force is exerted on each object. In general-term "To Push or Pull an Object" is defined as the force. The force is the interaction experience by the object be 11 min read Push and Pull ForceA push force or pull force is a force upon an object arising from the object's or body’s interaction with another object. A push or pull only exists as a result of an interaction, like when a body, an object or a material is either pushed or pulled, which is termed as a force. A force due to action 11 min read Interaction of ForcesBefore we explore how force can affect the state of motion of a body, let’s first look at what force is. Force is an interaction between two or more bodies that, when unopposed, causes a change in the state of motion of an object.By the definition of force, it is clear that force is something that c 9 min read Exploring ForcesA force is a push or pull upon a body of any mass resulting from the body's interaction with another body. Whenever there is an interaction between two bodies, there is a force upon each of the bodies. This article will discuss what force is, exploring forces, types of forces, and the effect of forc 5 min read Change in State of MotionIn science, a push or pull of an entity is identified as a Force. The interaction between two objects arises from the force. Force has both magnitude and direction. The strength of a force is articulated in magnitude. Force brings about an altar in the direction or state of motion of a body. Charact 11 min read Types of ForcesForces are an external cause that makes a body move, stop, and increase its velocity and other. There are various types of forces in physics and they are generally classified into two categories that are, Contact Force and Non Contact Force. In general, we define a push and pull as a force, and forc 14 min read Contact and Non Contact ForcesContact and Non-Contact Forces are the two main types of forces. Contact Force is a force that acts between objects in contact with each other. For example, Contact force can be experienced when an object is sliding on a surface, due to frictional force. However, Non-Contact Force does not require a 7 min read What is Pressure?Have you ever thought about why a needle is so thin, why fence spikes are pointed, or why a hammer's head is flat? It’s all about pressure. Pressure is the force applied to a specific area. A needle’s sharp tip concentrates the force, allowing it to easily pierce fabric. If it were blunt, the force 7 min read Fluid PressureFluid pressure is a measure of the force exerted by a fluid (liquid or gas) per unit area. It is a fundamental concept in fluid mechanics and has important implications in various scientific and engineering disciplines.In this article, we will learn about Fluid Pressure, its formula, units and examp 7 min read Atmospheric PressureAtmospheric pressure is the force exerted by the weight of the air above a given point on Earth's surface. It is a crucial aspect of atmospheric science and has various implications for weather, aviation, and everyday life. Atmospheric Pressure is about 1.01325 Pascal at sea level. Our body itself i 13 min read Chapter 2: FrictionFriction: A Necessary EvilIn Daily Life, You might have seen a vehicle slowing down, or you also have stopped your cycle by applying break whenever needed. Did you notice that an object moving on another object’s surface stops after some time when no external force is applied? Have you ever think about why this happened? Hav 6 min read Factors Affecting FrictionFriction is an opposing force that restricts the motion of one body over the surface of another body in contact with it. It is absolutely necessary for the motion of any object over another. It is like a necessary evil that harms and helps. Its dual function can be explained by the example of walkin 11 min read Types of FrictionFriction is a force between two surfaces that are sliding, or trying to slide, across each other. For example, when you try to push a book along the floor, friction makes this difficult. Friction always acts in the opposite direction to the movement of the object i.e. it opposes the motion of an obj 7 min read Static and Kinetic FrictionFriction is a force resisting relative motion and it occurs at the interface between the bodies, but also within the bodies, like in case of fluids. The concept of friction coefficient was first formulated by Leonardo da Vinci. The magnitude of the coefficient of friction is determined by the proper 12 min read Limiting FrictionLimiting friction is defined as the friction which is generated between the two static surfaces that come in contact with each other. The maximum friction that can be generated between two static surfaces in contact with each other. Once a force applied to the two surfaces exceeds the limiting frict 6 min read Sliding FrictionSliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction. That's why it's easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can 9 min read Fluid FrictionFluid friction occurs between fluid layers that are moving relative to each other. This internal resistance to flow is called viscosity or viscous drag or fluid friction. In normal terms, the viscosity of a fluid is described as its "thickness" of the fluid. Thus, water is "thin", having a lower vis 10 min read Increasing and Reducing FrictionThe force that acts between two bodies which are sliding or trying to slide against each other is known as friction. For example, when we push a box along a rough floor, friction is responsible for making the task difficult. Friction is also known as an opposing force since it always acts in the opp 8 min read Chapter 3: SoundSound Produced by a Vibrating BodyMusic connects in places where words cannot be heard. Music and sound are a part of our daily lives. A sound is a type of energy that provides us with the ability to hear. We view items around us by sensing light from them with our eyes. Similarly, ears are employed to sense sound. The vibration of 6 min read How is Sound Produced by Humans?Music or sound is a necessary component of life. Life would be bored and bitter without it. Sound, in general, is a source of energy that allows us to understand. Have you ever considered how it is produced by multiple instruments and living organisms? Vibrations allow it to be generated. We sense w 5 min read Sound Needs a Medium for PropagationWithout sound life is a little tough, isn't it? Like imagine watching a horror movie without sound you will realize that the scary movie becomes a funny video compilation. We are totally connected to sound, from morning to our bedtime we hear several sounds some sounds good but at the same time, som 6 min read How do we hear?Sound is produced from a vibrating object or the organ in the form of vibrations which is called propagation of sound and these vibrations have to be recognized by the brain to interpret the meaning which is possible only in the presence of a multi-functioning organ that is the ear which plays a hug 7 min read Amplitude, Time Period and Frequency of a VibrationSound is a form of energy generated by vibrating bodies. Its spread necessitates the use of a medium. As a result, sound cannot travel in a vacuum because there is no material to transfer sound waves. Sound vibration is the back and forth motion of an entity that causes the sound to be made. That is 5 min read Pitch and LoudnessOne comes across various forms of sound in its daily lives, and everyone is well-equipped with a system to recognize various types of differences in the sound pattern. When a mother speaks to her child, her accent is distinct from that of the child. And all these variations are due to a mechanism ca 7 min read Audible and Inaudible SoundsWe hear sound whenever we talk, listen to some music, or play any musical instrument, etc. But did you ever wondered what is that sound and how is it produced? Or why do we hear to our own voice when we shout in a big empty room loudly? What are the ranges of sound that we can hear? In this article, 10 min read Noise PollutionNoise pollution is the pollution caused by sound which results in various problems for Humans. A sound is a form of energy that enables us to hear. We hear the sound from the frequency range of 20 to 20000 Hertz (20kHz). Humans have a fixed range for which comfortably hear a sound if we are exposed 8 min read Chapter 4: Chemical Effects of Electric CurrentDo Liquids Conduct Electricity?An electric current passing through a conductive solution generates a chemical reaction. This may result in the production of gas bubbles on the electrodes, metal deposits on the electrodes, changes in the color of solutions, and so on. It is known what is current and how it is produced. Anything wh 7 min read Chemical Effects of Electric CurrentChemical reactions occur when an electric current flows through a conducting material. This chemical action of electric current is termed the Chemical Effect of Electric Current. For example, Hydrogen and oxygen separate from water when an electrical current is applied to it. Over the negative pole, 7 min read Electroplating | Definition, Principle, Process And UsesElectroplating refers to the process of coating a metal onto another metal or alloy with the help of an electric current. It is also known as electrochemical deposition or electrodeposition. Let's learn the electroplating process in detail, including its working principle, advantages, examples and u 6 min read Chapter 5: Some Natural PhenomenaWhat is Lightning?During thunderstorms, air currents move upwards and water droplets move down. This causes the separation of charges between clouds and between clouds and earth. When the magnitude of charges will increase, air (normally a foul conductor) starts conducting and permits the flow of electricity. This is 5 min read How Lightning Works?It is often seen a bright flash of light in the clouds followed by a sound called thunder. This bright flash of light is known as lightning. Lightning is an electric discharge in the atmosphere that happens when two oppositely charged clouds collide or when a charged cloud collides with the earth. I 7 min read Electric ChargeElectric Charge is the basic property of a matter that causes the matter to experience a force when placed in a electromagnetic field. It is the amount of electric energy that is used for various purposes. Electric charges are categorized into two types, that are, Positive ChargeNegative ChargePosit 8 min read Earthquake - Definition, Causes, Effects, ProtectionEarthquake is a natural phenomenon that manifests itself as a sudden shaking or trembling of the earth that lasts just a few seconds. It occurs as a result of disruption deep within the earth's crust or as a result of disturbances within the earth's crust. Earthquakes often occur deep inside the ear 6 min read What causes an Earthquake?One of the dangerous and major natural disasters that take place is the Earthquake. Due to earthquakes every year huge damage to property and life is caused all around the world. Therefore, developing countries implement proper strategies and awareness about the disaster management of the earthquake 7 min read Chapter 6: LightLaws of ReflectionLaws of Reflection is a principle or rule that governs the phenomenon of reflection of light. The law of reflection states that a light ray will reflect off a surface at the same angle that it hit it when it comes into contact with it. The angle at which a light beam strikes a surface is known as th 11 min read Regular and Diffused ReflectionThe light gets reflected from the surfaces. Any surface which is polished or in other words is shiny always acts like a mirror. The observation of light bouncing off the surfaces is termed reflection. The light after reflection travels in the same medium from where the ray was incident on the surfac 4 min read Multiple Reflections of LightThe process of bouncing back light rays which fall on the surface of an object, is called the reflection of light. A plane mirror reflects almost all the light that falls on it. In order to study and observe the reflection of light, we need an apparatus that can produce a thin beam of light. In othe 8 min read Dispersion of LightA rainbow shining against a gloomy stormy sky is a sight that everyone loves. How does sunshine shining through pure raindrops produce the rainbow of colors observed? A transparent glass prism or a diamond uses the same method to break white light into colors. There are about six colors in a rainbow 8 min read Human EyeHuman eye is one of the most beautiful and complex human organs. This is used to see various objects. The eye allows us to see the beautiful world around us. It allows us to see various colors, visualize various objects, and help to identify various objects around us. We can compare the human eye to 11 min read Braille System - Light | Class 8 PhysicsBraille is a system developed by Louis Braille in 1824 to help visually challenged people. It is a code by which languages such as English, French, Spanish, etc can be written and read by people that have defects in there eyes. This code consists of raised dots, that can be read with fingers by blin 3 min read Chapter 7: Stars and the Solar SystemWhat is a Star? Formation, Life Span, ConstellationsThe night sky is filled with brilliant stars. Stars, like the sun, emit their own light. The Sun is millions of times further distant than the stars. As a result, they seem to us as points with a considerably larger Sun. During the day, stars can be seen in the sky, but they are obscured by the inte 9 min read The Moon and Lunar eclipseCelestial bodies include planets, stars, the moon, and other celestial bodies. Astronomy is a field of science concerned with the study of heavenly bodies and their phenomena. One of the findings of celestial bodies that we may create is the shift in the appearance of the moon every day. The full mo 12 min read Artificial SatellitesWhen looked at the night sky many heavenly bodies like stars, moon, satellites, etc are observed in the sky. Satellites are small objects revolving or orbiting around a planet or on object larger than it. The most commonly observed and known satellite is the moon, the moon is the satellite of Earth, 8 min read Like