CBSETUTOR.aiCBSETUTOR.ai
India's #1 AI Tutorimportant-questions · Science · Chapter 9

Important Questions: CBSE Class 8 Science Chapter 9 Friction

Chapter 9 Friction is a scoring chapter in CBSE Class 8 Science, contributing 5 to 7 marks in the annual board exam. Questions range from 1-mark objective items testing definitions to 5-mark case studies on real-world applications of friction. Understanding the types of friction, factors that affect it, the role of fluids, and methods to reduce friction is essential. This page organises 18 carefully selected important questions by marks weightage, complete with model answers aligned to NCERT terminology, so you can practice exactly what examiners expect.

Your child's private AI tutor — trained on NCERT.
3-day free trial · ₹1 to start · Cancel anytime.
Start 3-day free trial →

Key takeaways

  • ✓Chapter 9 Friction typically carries 5-7 marks in the CBSE Class 8 Science annual exam across different question types.
  • ✓Types of friction—static, sliding, rolling—and their comparative magnitudes form the backbone of 2-mark and 3-mark questions.
  • ✓Factors affecting friction (nature of surfaces, normal force) are tested through numerical and reasoning-based questions.
  • ✓Fluid friction concepts appear in higher-order thinking questions and case-based scenarios worth 4-5 marks.
  • ✓CBSE often asks students to differentiate between friction types or explain why friction is both friend and foe in 3-mark format.
  • ✓Diagram-based questions on ball bearings, treaded tyres, or streamlined shapes are common in 2-mark sections.
  • ✓Common mistakes include confusing static friction with limiting friction and not stating units in numerical problems.

Chapter Overview and Marks Weightage in CBSE Exam

Chapter 9 Friction introduces students to the force that opposes relative motion between surfaces in contact. The chapter is part of Unit 4: Effects of Current in the broader CBSE syllabus, though friction itself is a standalone mechanics topic. In the annual Class 8 Science exam, friction typically accounts for 5 to 7 marks distributed across multiple question formats. Expect one 1-mark MCQ or fill-in-the-blank, one or two 2-mark short-answer questions, one 3-mark descriptive or diagram-based question, and occasionally a 4 to 5-mark case-based integrated question linking friction to energy or motion. Internal assessments and periodic tests in schools such as Delhi Public School chains and Kendriya Vidyalayas also draw heavily from this chapter because it lends itself well to numericals and application-based reasoning.
  • 1-mark questions: definitions, true/false, MCQs on friction types
  • 2-mark questions: advantages/disadvantages, factors affecting friction, labelled diagrams
  • 3-mark questions: differentiate friction types, explain rolling vs sliding, methods to reduce friction
  • 5-mark questions: case studies on vehicles, streamlining, or sports surfaces

1-Mark Questions: MCQs and Very Short Answer (VSA)

One-mark questions test recall and basic conceptual clarity. CBSE frames these as multiple-choice questions, true/false statements, or fill-in-the-blank items. They often ask for the definition of friction, identification of friction type from a scenario, or a single-word answer about methods to reduce friction. These questions appear in Section A of the question paper and are meant to be answered in under one minute each. Practice speed and accuracy here; every mark counts toward your final percentage.

2-Mark Questions: Short Answer Type

Two-mark questions require brief explanations, lists, or simple diagrams. CBSE typically asks students to state two advantages or disadvantages of friction, explain one method to reduce friction with an example, or draw and label a simple diagram such as a ball bearing assembly. Answers should be concise—two to three sentences or two clear points. Use NCERT language wherever possible, for instance saying 'nature of surfaces in contact' rather than vague terms like 'smoothness'. Marks are split: one for content accuracy and one for clarity or diagram correctness. Many students lose half a mark by omitting labels or not writing in complete sentences.

3-Mark Questions: Descriptive and Application-Based

Three-mark questions demand deeper understanding and the ability to explain concepts in three to four sentences or to compare and contrast two ideas. Common question stems include 'Differentiate between...', 'Explain why...', 'How does... affect friction?', and 'Describe the role of friction in...'. CBSE mark schemes allocate one mark per distinct valid point, so structure your answer in three clear parts. For example, if asked to differentiate static and sliding friction, state the definition of each (1 mark), compare their magnitudes (1 mark), and give a real-world example of each (1 mark). Avoid writing long paragraphs; use bullet points or numbered statements internally if the question permits. Examiners appreciate clarity and logical flow.

5-Mark Questions: Case-Based and Long Answer

Five-mark questions are designed to test analytical thinking, application, and the ability to integrate multiple concepts. CBSE introduced case-based questions in recent years, presenting a real-world scenario or passage (100-150 words) followed by sub-questions totalling five marks. For Chapter 9 Friction, a case might describe a car journey on different road surfaces or the design of sports shoes, then ask sub-questions on friction types, factors, and advantages. Alternatively, a traditional long-answer question might ask you to describe all methods to reduce friction with examples and diagrams. Allocate about eight to ten minutes for a 5-mark answer. Structure it with a brief introduction, three to four well-explained points or sub-answers, and a concluding sentence if space permits. Diagrams, when relevant, can fetch an extra mark for presentation.
  • Read the case passage twice and underline key terms before attempting sub-questions.
  • Answer each sub-part separately; do not merge them into one paragraph.
  • Use headings like (i), (ii), (iii) if the question has sub-parts.
  • Include at least one diagram or flowchart if the question asks to 'explain' or 'describe'.

More 5-Mark and 4-Mark Practice Questions

Beyond case studies, CBSE also sets traditional long-answer questions worth four or five marks asking students to describe friction comprehensively. These questions often begin with 'Describe in detail...', 'Explain with examples...', or 'List and explain all methods...'. A strong answer will cover definitions, types, factors, advantages, disadvantages, and real-life applications in a logical sequence. Use subheadings or bullets to organize your response so the examiner can quickly spot each scoring point. Remember that presentation matters: neat handwriting, underlining key terms, and clear diagrams can earn you grace marks. Schools like Army Public Schools and Kendriya Vidyalayas train students to write structured answers, and sample papers from previous years show that well-organised responses score higher even if content is similar.

How CBSE Frames Questions from Chapter 9 Friction

CBSE question paper setters follow specific patterns when designing questions for Chapter 9 Friction. They draw heavily from NCERT in-text questions, exercises, and activities. Around sixty percent of questions are direct or slightly reworded versions of NCERT exercise problems. The remaining forty percent test application and higher-order thinking skills, especially in 3-mark and 5-mark questions. CBSE loves to ask 'Why?' and 'How?' rather than just 'What?'. For example, instead of asking 'What is friction?', they ask 'Why is friction essential for walking?' or 'How does oiling reduce friction in machines?'. Diagram-based questions are popular: expect to draw and label ball bearings, tyre treads, or streamlined shapes. Another favourite is the 'Assertion-Reason' format introduced in recent years, where you must judge whether both statements are true and whether the reason correctly explains the assertion. Numericals are rare in Class 8 friction but may appear as semi-quantitative reasoning, such as comparing magnitudes of friction types. Competency-based questions link friction to real-world problem-solving, like choosing the right shoe sole for a rainy day or explaining why luggage trolleys have wheels.
  • Direct NCERT questions: ~60 percent of total marks, especially 1-mark and 2-mark items.
  • Application-based: ~25 percent, focusing on everyday examples like sports, vehicles, and household activities.
  • Higher-order thinking: ~15 percent, including case studies, assertion-reason, and multi-concept integration.
  • Diagram questions: at least one per exam, usually worth 2 marks.
  • Common question verbs: 'Differentiate', 'Explain why', 'List and explain', 'Describe the role of', 'How does... affect'.

Common Mistakes Students Make in Friction Answers

Even students who understand friction concepts well often lose marks due to presentation errors and conceptual slips. One frequent mistake is confusing static friction with limiting friction—they are not the same; static friction can vary from zero up to a maximum value called limiting friction. Another error is stating that friction depends on the area of contact; NCERT clearly says friction is independent of contact area for the same normal force. In numerical or reasoning questions, students forget to mention that friction opposes relative motion, not all motion, leading to vague answers. Diagrams are a common pitfall: forgetting to label parts, drawing arrows in the wrong direction, or omitting the title costs easy marks. When explaining methods to reduce friction, many write only 'use oil' without clarifying that oil acts as a lubricant by forming a thin layer. In differentiation questions, students sometimes list points for only one term instead of comparing both side by side. Finally, handwriting and neatness matter more than students realise; examiners mark hundreds of papers, and a well-organised, legible answer stands out and often receives the benefit of doubt for borderline points.
  • Mistake 1: Writing 'friction depends on area of contact'—it does not; it depends on nature of surfaces and normal force.
  • Mistake 2: Using the terms static friction and limiting friction interchangeably without explanation.
  • Mistake 3: Not drawing force arrows in diagrams or labelling them as F_friction, F_applied, etc.
  • Mistake 4: Giving one-word answers in 2-mark or 3-mark questions instead of explaining in sentences.
  • Mistake 5: Omitting units or examples when the question asks for them.
  • Mistake 6: Writing long paragraphs instead of point-wise answers for differentiation or listing questions.

Additional Important Questions: Mixed Practice Set

This section compiles five more exam-style questions across different mark categories to give you varied practice. Attempt these under timed conditions—allocate one minute for 1-mark, two minutes for 2-mark, four minutes for 3-mark, and eight minutes for 5-mark questions. After writing your answers, compare them with the model answers provided. Focus on matching the structure and using precise NCERT terminology. If you find gaps in your understanding, revisit the relevant NCERT section or refer to Class 8 Science solutions available on educational platforms. Regular practice with these question formats will build speed and confidence, both essential for scoring well in the annual CBSE exam and internal assessments. Many Kendriya Vidyalayas and Navodaya Vidyalayas use similar question banks for periodic tests, so mastering these patterns benefits you throughout the academic year.

How CBSETUTOR.ai Helps You Master Friction and Score Higher

Chapter 9 Friction is concept-heavy and application-rich, which means solving varied questions is the key to mastery. CBSETUTOR.ai offers a 24×7 AI tutor designed specifically for CBSE students from Class 6 to 12. You can upload a photo of any friction problem—whether from your school worksheet, NCERT exercise, or a sample paper—and receive step-by-step solutions in seconds. The AI tutor explains each step using NCERT language, highlights common errors, and even suggests similar practice questions. For just ₹999 per month, you get unlimited question solving, chapter-wise tests, and instant doubt clearing for every subject. That is one flat price for all classes, with no hidden fees. Parents across Delhi NCR, Mumbai, Bengaluru, and Tier-2 cities appreciate the affordability and convenience: no commute to coaching centres, no waiting for the next tuition class. Start with a free 3-day trial to see how quickly your child gains confidence in answering friction questions and other tough Science chapters.
  • Photo-upload solving: snap your friction question and get detailed answers instantly.
  • Chapter-wise question banks: practice 50+ questions for Chapter 9 with model answers.
  • Mistake alerts: the AI highlights common errors like confusing friction types or missing labels.
  • Affordable: ₹999/month for Classes 6-12, all subjects. 3-day free trial, cancel anytime.
  • Available 24×7: get help at 11 PM before the exam or early morning before school.

Revision Tips and Exam Strategy for Friction Questions

In the final week before your CBSE Class 8 Science exam, focus on active recall rather than passive reading. Make a two-column chart: in the left column list all key terms (static friction, sliding friction, rolling friction, fluid friction, factors affecting friction, methods to reduce friction), and in the right column write a one-sentence definition or example for each. This serves as a quick-reference sheet. Practice drawing diagrams—ball bearings, treaded tyres, streamlined fish—until you can sketch and label them in under one minute. Solve at least ten previous-year questions or sample-paper questions from Chapter 9 under timed conditions. Identify your weak spots: are you losing marks in definitions, explanations, or diagrams? Allocate extra practice time to that area. On exam day, read each friction question twice before writing; many students misinterpret 'differentiate' as 'define' and lose marks. Use the first minute to jot down a rough outline of your answer in the margin, then write the final answer neatly. For 5-mark case-based questions, underline or highlight key phrases in the passage that hint at the answer. Finally, leave two minutes at the end to review your friction answers: check that all diagrams are labelled, all numerical answers have units, and all points are written in complete sentences. These small habits can lift your score by three to five marks, making a significant difference in your overall percentage.
  • Create a one-page summary sheet with definitions, types, factors, and methods to reduce friction.
  • Practice at least five diagram-based questions with labelling under timed conditions.
  • Solve previous-year CBSE papers: friction appears in almost every year's paper.
  • Use mnemonics: SLR (Static > Sliding > Rolling) for friction magnitude order.
  • Review NCERT in-text and end-of-chapter questions one day before the exam—sixty percent of exam questions mirror these.
  • In the exam, allocate time proportionally: 1 mark = 1 minute, 5 marks = 8-10 minutes.

Frequently asked questions

How many marks does Chapter 9 Friction carry in the CBSE Class 8 Science annual exam?+
Chapter 9 Friction typically carries 5 to 7 marks in the CBSE Class 8 Science annual exam. Questions range from 1-mark MCQs to 5-mark case-based or long-answer questions, distributed across different sections of the paper.
What are the most important topics in Chapter 9 Friction for the exam?+
The most important topics are types of friction (static, sliding, rolling, fluid), factors affecting friction (nature of surfaces, normal force), methods to reduce friction (lubricants, ball bearings, polishing, streamlining), and real-life applications and disadvantages of friction. CBSE frequently asks differentiation and application-based questions from these areas.
How should I answer a 'differentiate between' question on friction types?+
Structure your answer in three parts: define each friction type clearly, compare their magnitudes or conditions of occurrence, and give a real-world example of each. Use bullet points or a two-column table if the question allows, and write in complete sentences to earn full marks.
Are diagrams compulsory in friction answers?+
Diagrams are not always compulsory, but if the question says 'draw and label' or 'explain with a diagram', you must include one. Even when not explicitly asked, adding a neat labelled diagram (e.g. ball bearings, treaded tyre) can earn you an extra presentation mark in 3-mark or 5-mark answers.
Does friction depend on the area of contact between surfaces?+
No. Friction is independent of the area of contact, provided the normal force and nature of surfaces remain constant. This is a common misconception; NCERT clearly states that friction depends on the nature of surfaces in contact and the normal force, not the contact area.
What is the difference between static friction and limiting friction?+
Static friction is the frictional force that acts when an object is at rest and can vary from zero up to a maximum value. Limiting friction is that maximum value of static friction, beyond which the object starts moving. Many students use these terms interchangeably, which is incorrect.
How can I score full marks in case-based questions on friction?+
Read the case passage carefully and underline key terms. Answer each sub-question separately using headings like (i), (ii), (iii). Use NCERT terminology, give specific examples from the passage, and write in complete sentences. Allocate marks proportionally—if a sub-part is worth 2 marks, write at least two distinct points.
Which friction is the largest: static, sliding, or rolling?+
Static friction (or more precisely, limiting static friction) is the largest, followed by sliding friction, and then rolling friction, which is the smallest. This order is important for answering comparison and magnitude-based questions correctly.
What are the common mistakes to avoid in friction answers?+
Common mistakes include stating that friction depends on area of contact, confusing static and limiting friction, forgetting to label diagrams, writing one-word answers for multi-mark questions, omitting units in numerical problems, and using vague language instead of precise NCERT terms like 'nature of surfaces in contact' or 'normal force'.
How does CBSETUTOR.ai help with Chapter 9 Friction preparation?+
CBSETUTOR.ai provides a 24×7 AI tutor where you can upload photos of friction questions and receive instant step-by-step solutions in NCERT language. You also get chapter-wise question banks, mistake alerts, and unlimited doubt clearing for ₹999 per month—one price for all classes. A 3-day free trial is available to test the platform before subscribing.
Can I expect numerical problems from Chapter 9 Friction in Class 8?+
Pure numerical problems are rare in CBSE Class 8 for Chapter 9 Friction. However, you may see semi-quantitative reasoning questions, such as comparing magnitudes of friction types or explaining how changing the normal force affects friction. Focus on conceptual understanding and application rather than calculations.
How much time should I spend on a 5-mark friction question in the exam?+
Allocate about 8 to 10 minutes for a 5-mark question. Spend 1-2 minutes reading and planning your answer, 6-7 minutes writing, and 1 minute reviewing for completeness, labels, and neatness. This ensures you cover all scoring points without rushing.

Related resources

Class 8 Science Chapter 9 Friction — Formulas & Key PointsCBSE Class 8 Science Chapter 9 Friction Worksheet with AnswersCBSE Class 8 Science Chapter 8 Force and Pressure Worksheet with AnswersImportant Questions: CBSE Class 8 Science Chapter 8 Force and PressureAI Tutor for Class 8: The Smart Alternative to TuitionAI Tutor for Class 8 Social Science: Learn Faster with Instant HelpOnline Class 9 Science Tutor in Mumbai – 24/7 CBSE-Aligned AI CoachingImportant Questions: CBSE Class 9 Mathematics Chapter 2 Polynomials

Keep learning — related guides

Class 8Science
Class 8 Science Tutor in Andheri West Mumbai - 24×7 Help
Class 8Science
Class 8 Science Chapter 13 Light — Formulas & Key Points
Class 8Science
Important Questions: CBSE Class 8 Science Chapter 13 Light
Class 8Science
CBSE Class 8 Science Chapter 13 Light Worksheet with Answers
Class 8Science
Class 8 Science Chapter 12 Some Natural Phenomena — Formulas & Key Points
Class 8Science
Important Questions: CBSE Class 8 Science Chapter 12 Some Natural Phenomena

Ready to give your Class 8 child the tutor that never sleeps?

CBSETUTOR.ai covers every chapter in the Class 8 NCERT syllabus — Maths, Science, Social Science, English, Hindi and more. 24×7. Patient. Unlimited. 3-day free trial.

Start your child's 3-day free trial →