NCERT Solutions for Class 8 Science Chapter 12 Friction

Welcome to the study of Friction Class 8, which is Chapter 12 in the NCERT Solutions for Class 8 Science. In this chapter, we will explore the concept of friction, its definition, and its importance in our daily lives.

So, what is friction in Class 8? Friction is a force that opposes the motion of objects. It plays a crucial role in how we walk, drive, and even write. Understanding friction helps us learn about the different types of friction, such as static friction, kinetic friction, and rolling friction.

In this chapter, you will find Friction Class 8 questions and answers that will help clarify your understanding. We will also discuss the types of friction in Class 8, which will give you a deeper insight into how friction affects various activities.

For easy reference and study, you can access the Friction Class 8 PDF that contains all the important concepts and solutions. NCERT Solutions provided will guide you through each topic step by step, making it easier to grasp the material.

What is Friction Class 8?

Friction is the force that resists the motion of one object sliding or moving over another. When two surfaces are in contact, friction opposes their movement and acts in the opposite direction of motion. This force is crucial in our daily lives as it helps us walk, drive, and perform many activities.

Types of Friction Class 8:

1. Static Friction:
   • It occurs when an object is not moving and tries to resist the start of motion.
2. Sliding Friction:
   • This type of friction happens when an object slides over a surface, such as dragging a box across the floor.
3. Rolling Friction:
   • This friction comes into play when an object rolls over a surface, like a ball rolling on the ground.
4. Fluid Friction:
   • This occurs when objects move through fluids (liquids or gases), like a swimmer moving through water or an airplane flying in the air.

Class 8 Science Chapter 12 Question Answer PDF

To help you study, we have created a Friction Class 8 PDF that includes all the important points from the chapter. You will also find friction class 8 questions answers to test your understanding and prepare for your exams.

This material follows the Class 8 Science Syllabus, so you can be sure you are covering everything you need. If you want more help, our NCERT Solutions for Class 8 Science provide clear explanations and step-by-step answers to all the questions in your textbook.

FRICTION

Friction Class 8 Questions Answers

Q1. Fill in the blanks.

a) Friction opposes the relative motion between the surface in contact with each other.

b) Friction depends on the nature of surfaces.

c) Friction produces

d) Sprinkling of powder on the carrom board reduces.

e) Sliding friction is smaller than the static friction.

Q2. Four children were asked to arrange forces due to rolling, static, and sliding frictions in a decreasing order. Their arrangements are given below. Choose the correct arrangement.

a) Rolling static, sliding b) Rolling, sliding, static

c) Static, sliding, rolling d) Sliding, static, rolling

Ans:

Q3. Alida run her car on dry marble floor. Wet marble floor, news paper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be.

a) Wet marble floor, dry marble floor, newspaper and towel.

b) Newspaper, towel, dry marble floor, wet marble floor.

c) Towel, newspaper, dry marble floor, wet marble floor.

d) Wet marble floor, dry marble floor, towel, newspaper

Ans: a) Wet marble floor, dry marble floor, newspaper and towel.

Q4. Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.

Ans: Frictional force will act upwards i.e., direction opposite to that of sliding book.

Q5. You spill a bucket of soapy water on a marble floor accidently. Would it make it easier or more difficult for you to walk on the floor ? Why.

Ans: It is difficult to walk on a soapy floor because soapy floor applies very less friction and hence we can slip on such floor.

Q6.Explain why sports men use shoes with spikes.

Ans: It is done to provide the shoes better grip on the ground, so it increases the friction and prevent slipping.

Q7. Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why ?

Ans: We know that the force of friction is increased if the two surfaces pressed harder. A heavier box will apply more pressure on the floor and hence Seema will experience more frictional force.

Q8. Explain why sliding friction is less than static friction

Ans: 1) The sliding friction is less than static friction because of the inter locking of irregularities in the two surfaces.

2) When the object starts sliding the contact points on its surface do not get enough time to lock into the contact points on the floor.

3) So the sliding friction is less than static friction.

Q9. Give examples to show that friction is both a friend and foe.

Ans:Friction as a Foe : Machine parts that come in contact with one another wear out because of friction. Similarly the soles of our shoes wear out because of friction.

Friction as a Friend : Frictional force is very useful in several situations. If there were no friction between the wheels and the road, no vehicle would be able to move. If there were no brakes for a bicycle there would be many accidents.

Q10. Explain why object moving in fluids must have special shapes ?

Ans: When object move through fluids they have to overcome the friction acting on them. Efforts are therefore made to minimize the friction so objects are given special shapes. Idea of such shapes come from the body structure of birds and fishes. Which have to move about in fluids all the time. Such shapes are called streamlined. Giving such shapes to the ships, plane and cars is called streamlining.

Q11. Can we reduce friction to zero by polishing surface (or) using large amounts of lubricants?

Ans: No, Friction can never be entirely eliminated. No surface is perfectly smooth. Same irregularities are always there.

Class 8 Science Friction MCQs with Answers

Q1. What is the force that opposes the motion of an object called?

a) Gravity

b) Magnetism

c) Friction

d) Pressure

Ans: c) Friction

Explanation Friction is the force that acts against the motion when two surfaces are in contact, trying to stop or slow down the object.

Q2. Which of the following types of friction occurs when an object is at rest?

a) Sliding friction

b) Static friction

c) Rolling friction

d) Fluid friction

Ans: b) Static friction

ExplanationStatic friction prevents an object from moving when it is at rest. It must be overcome to initiate motion.

Q3. Which type of friction occurs when an object moves through water or air?

a) Static friction

b) Sliding friction

c) Rolling friction

d) Fluid friction

Ans: d) Fluid friction

Explanation Fluid friction occurs when objects move through fluids (liquids or gases), like a swimmer moving through water or an airplane flying in the air.

Q4. Which type of friction is the smallest and allows objects like wheels to move easily?

a) Sliding friction

b) Static friction

c) Rolling friction

d) Fluid friction

Ans: c) Rolling friction

ExplanationRolling friction is usually smaller than both sliding and static friction, which is why wheels make it easier to move heavy objects.

Q5. Why is friction necessary for walking?

a) It helps us to glide smoothly

b) It opposes motion

c) It provides grip for our feet to push against the ground

d) It slows us down

Ans: c) It provides grip for our feet to push against the ground

Explanation Without friction, our feet would slip, making walking difficult. Friction helps in providing a firm grip to walk properly.

Q6. How can friction between two surfaces be reduced?

a) Increasing the roughness of the surfaces

b) Applying oil or grease

c) Increasing the weight of the object

d) Applying more pressure

Ans: b) Applying oil or grease

Explanation Lubricants like oil or grease reduce the contact between the surfaces, thus reducing the friction.

Q7. Which of the following statements is true about friction?

a) Friction always helps in movement

b) Friction only occurs in solids

c) Friction opposes the relative motion between surfaces

d) Friction is independent of the type of surfaces in contact

Ans: c) Friction opposes the relative motion between surfaces

Explanation Friction always acts to resist or oppose the relative motion of two surfaces in contact.

Q8. What is the relationship between friction and the surface area of contact?

a) Friction increases with an increase in surface area

b) Friction decreases with an increase in surface area

c) Friction does not depend on surface area

d) Friction decreases with the weight of the object

Ans: c) Friction does not depend on surface area

Explanation Friction primarily depends on the nature of the surfaces in contact and the normal force, not the surface area of contact.

Q9. Which factor does NOT affect friction?

a) Nature of the surfaces in contact

b) Mass of the object

c) Area of the contact surface

d) The normal force between the surfaces

Ans: c) Area of the contact surface

Explanation Friction is affected by the nature of the surfaces (smooth or rough) and the normal force, but not by the contact area.

Q10. Why is it easier to push a box on a smooth surface than on a rough surface?

a) The box is lighter on a smooth surface

b) The smooth surface has less friction

c) The box becomes stronger on a smooth surface

d) The weight of the box decreases on a smooth surface

Ans: b) The smooth surface has less friction

Explanation A smooth surface offers less friction, making it easier to move the box as compared to a rough surface.

Class 8 Science Chapter 12 NCERT Solutions – Free PDF Download

You can easily download the NCERT Solutions for Class 8 Science Chapter 12 on Friction as a free PDF. This resource helps students understand the chapter thoroughly, making it easier for them to prepare for their exams. The solutions are organized in a way that builds a strong foundation in the topic, ensuring that anyone can succeed in their board exams. Our subject experts have created these solutions to help students grasp important concepts, formulas, and how to solve numerical problems effectively.

Chapter 12 – Friction NCERT Solutions for Class 8 Science Chapters

Chapter 12, which focuses on Friction, is part of the CBSE Class 8 Syllabus and is included in the Physics section of the NCERT Science textbook. It explains the concept of friction in simple terms, along with its causes and relevant formulas. To enhance understanding, diagrams and illustrations are provided to show how friction works in real life. The vocabulary, examples, and numerical problems are presented step-by-step, making it easy for students to follow along.

In addition to this chapter, you can also find NCERT Solutions for Class 7 and other subjects that make studying more manageable. With these resources, students can revise effectively and improve their exam scores.

Weightage of Class 8 Science Chapter-Wise Marks

Class 8th Science Chapter 12 carries a 20-point weighting. From the standpoint of the exam, this chapter is crucial. Basic questions and difficult numerical problems recur in this subject’s Board exams. As a result, pupils who prepare using these study resources do better.

Here’s a breakdown of what’s in Chapter 12 Friction Class 8:

• 12.1Force of Friction (1 short)
• 12.2Factors affecting Friction (2 MCQ’s, 1 short)
• 12.3. Friction: A Necessary Evil (1 long)
• 12.4Increasing and Reducing Friction (1 short, 1 long)
• 12.5Wheels reduce Friction (1 short)
• 12.6Fluid Friction (2 MCQ’s, 1 short)

Why is it important to use NCERT Solutions for Class 8 Science Chapter 12?

• Topic-by-topic solutions are supplied, along with brief descriptions, simplified pictures, and detailed numerical answers.
• NCERT Solutions for Class 8 Science Chapter 12 Friction are written by a team of specialists who strive to make learning easy and enjoyable.
• Our simplified solutions make it simple to comprehend and give a fantastic learning experience for convenient exam revision.
• Important facts and interesting activities are included in NCERT Science (Physics) Class 8 Chapter 12 to help students learn the concept realistically.
• Our curriculum will help you improve your grades and complete your revision.
• Apart from that, these solutions include all of the chapter’s solved questions/answers and activities.

Class 8 Friction FAQ

What is friction, and why is it important in daily life?

Friction is the force that opposes the motion of an object when it comes into contact with another surface. It plays an essential role in our daily activities, such as walking, driving, and holding objects, as it provides the necessary grip to prevent slipping.

How can friction be reduced, according to NCERT Solutions for Class 8 Science Chapter 12?

Friction can be reduced by using lubricants like oil or grease, making the surfaces smoother, using wheels (rolling friction), or using air cushions. The solutions also explain how these methods help in reducing resistance between surfaces.

Why is rolling friction less than sliding friction?

Rolling friction is less than sliding friction because, in rolling, the object touches the surface at fewer points, reducing the area of contact and the amount of resistance. This concept is clearly explained in NCERT Solutions for Class 8 Science Chapter 12.

How do NCERT Solutions help in understanding the advantages and disadvantages of friction?

The solutions for Class 8 Science Chapter 12 explain both the pros and cons of friction. While friction helps in walking, holding objects, and stopping vehicles, it also causes wear and tear and generates heat, which can sometimes be undesirable.