NCERT Exemplar Solution for Class 8 Science Chapter-12 Friction
Friction is one of the most important concepts in everyday science because it affects almost every movement around us. Whether we walk on the road, write with a pencil, ride a bicycle, or stop a moving vehicle, friction plays a major role. Chapter 12 of Class 8 Science explains how friction works, why it is necessary, and how it can sometimes create difficulties in motion. The chapter introduces students to the causes of friction, factors affecting friction, fluid friction, and methods to increase or reduce it. The NCERT Exemplar Solution for Class 8 helps learners understand these ideas in a practical and interesting manner. Through activity-based questions and detailed explanations, students can improve their understanding of scientific concepts and prepare effectively for examinations. The NCERT Exemplar Solution is especially useful for strengthening conceptual clarity and developing logical thinking skills. Students who practice regularly with NCERT solutions for class 8 gain confidence in solving both theoretical and application-based questions related to friction and motion.
Find the PDF of NCERT Exemplar Solution for Class 8 Science Chapter-12 friction
Understanding Friction and Its Importance
Friction is the force that opposes the motion of one object moving over another. Whenever two surfaces come into contact, friction acts between them. This force slows down movement and can even stop objects completely. The chapter explains that friction is caused due to the irregularities present on the surfaces of objects. Even smooth surfaces have tiny uneven parts that create resistance during movement.
Students learn that friction is both useful and harmful. Without friction, walking would become impossible because our feet would slip on the ground. Vehicles would not be able to move properly, and writing with a pen or pencil would also become difficult. Friction provides grip, balance, and control in daily life activities. At the same time, excessive friction creates problems. It causes wear and tear in machines, produces heat, and wastes energy. This is why scientists and engineers develop methods to reduce friction in mechanical systems. Through exemplar questions, students understand the practical significance of friction in a simple and relatable manner.
Types of Friction and Their Effects
Chapter 12 introduces different types of friction and explains how each type affects motion differently. Students gain a clear understanding of static friction, sliding friction, rolling friction, and fluid friction.
Static and Sliding Friction
Static friction acts on objects that are at rest. It prevents movement until enough force is applied. For example, pushing a heavy box requires effort because static friction resists the motion initially. Sliding friction occurs when one object slides over another. It is lower than static friction but still slows down movement. When a book is pushed across a table, sliding friction acts between the book and the table surface.
The exemplar solutions explain how rough surfaces create more friction while smooth surfaces create less friction. This concept helps students understand why tyres have grooves and why athletes wear special shoes for better grip.
Rolling and Fluid Friction
Rolling friction acts when an object rolls over a surface. It is much smaller compared to sliding friction. This is why wheels are used in vehicles and machines to make movement easier.
Fluid friction, also called drag, acts when objects move through liquids or gases. Air resistance experienced by moving vehicles and water resistance faced by swimmers are examples of fluid friction. The chapter explains that the shape of objects can reduce fluid friction. Aeroplanes, ships, and cars are designed carefully to move smoothly through air or water. By practicing exemplar questions, students learn how different types of friction influence daily activities and technological advancements.
Methods to Increase or Reduce Friction
An important part of this chapter focuses on controlling friction according to need. Sometimes friction is increased for safety, while in other situations it is reduced for smooth functioning.
Friction can be increased by making surfaces rough. For example, shoe soles are designed with patterns to improve grip on the ground. Sand is spread on slippery roads during rainy seasons to prevent accidents. To reduce friction, lubricants such as oil and grease are used in machines. Ball bearings are also used in machines and vehicles because they convert sliding friction into rolling friction, making movement easier and reducing wear and tear.
The chapter also explains why machines become hot after continuous use. Friction generates heat energy when two surfaces rub against each other. This practical understanding helps students connect classroom learning with real-life experiences. The exemplar solutions provide well-structured answers to conceptual and activity-based questions, making revision easier before exams.
Role of NCERT Exemplar Questions in Exam Preparation
The NCERT Exemplar questions for Chapter 12 Friction are designed to test conceptual understanding and application skills. These questions encourage students to think scientifically and apply their knowledge to everyday situations.
Practicing NCERT Exemplar Solution helps students improve answer-writing skills and develop confidence in handling different question formats. The detailed explanations make complex concepts simple and easier to remember. Students also learn to explain scientific processes using proper terminology. Teachers often recommend exemplar questions because they provide additional practice beyond textbook exercises. Regular revision of these questions improves logical reasoning and prepares students for higher-level science topics in future classes.