Friction — Class 8 MCQs with Answers
Class 8 CBSE Science · Chapter 109
Pre-2026 syllabusThis chapter is from the older NCERT book. See the 2026-27 Class 8 Science chapters →
72 practice questions · 24 Easy · 24 Medium · 24 Hard · Updated
Practise the most important Class 8 CBSE Science questions from Chapter 109, "Friction". You get 6 timed quizzes made from 72 NCERT-based MCQs, with answers and explanations. The questions are split into 24 Easy, 24 Medium and 24 Hard. Warm up on the basics, then move on to the exam-level questions that set top scorers in CBSE Board exams apart.
To score well in "Friction", focus on clear concepts in physics, chemistry and biology basics. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This trains you to stay accurate under time pressure, as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on Friction, then move to Medium and Hard to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 8 Science mastery score. 14 sample questions are solved in full below, with the answer and a worked explanation. Sign in free to start practising.
Key concepts: Friction (Class 8 Science)
This chapter covers friction — its causes, types, advantages and disadvantages, and ways to increase or reduce it.
- Friction
- A force that opposes relative motion between surfaces in contact; it acts opposite to the applied motion.
- Cause of friction
- Irregularities (roughness) of the two surfaces interlocking; smoother surfaces have less friction.
- Types of friction
- Static (before motion), sliding and rolling friction; static > sliding > rolling for the same surfaces.
- Advantages & disadvantages
- Friction lets us walk, write and grip, but also wears out parts and wastes energy as heat.
Friction — important questions & MCQs with answers (Class 8 Science)
14 solved questions from this chapter's difficulty levels, each with its answer and explanation. The other 58 are timed and scored when you sign in.
- Q1Easy
Friction is a force that:
A.Opposes the motion of objects✓ CorrectB.Has no effectC.Speeds up motionD.Adds weightAnswer: A. Opposes the motion of objects
Explanation: Friction opposes the relative motion between surfaces in contact.
- Q2Easy
A rough surface produces ____ friction than a smooth surface.
A.LessB.NoC.More✓ CorrectD.EqualAnswer: C. More
Explanation: Rougher surfaces have more interlocking irregularities, so they produce more friction.
- Q3Easy
Friction between two surfaces produces:
A.Light onlyB.Sound onlyC.MagnetismD.Heat✓ CorrectAnswer: D. Heat
Explanation: Friction generates heat, which is why rubbing the hands warms them.
- Q4Easy
Substances applied between surfaces to reduce friction are called:
A.Lubricants✓ CorrectB.SolventsC.FuelsD.AdhesivesAnswer: A. Lubricants
Explanation: Lubricants such as oil and grease form a layer that reduces friction.
- Q5Easy
Which type of friction is the smallest?
A.Rolling friction✓ CorrectB.Sliding frictionC.All are equalD.Static frictionAnswer: A. Rolling friction
Explanation: Rolling friction is the smallest, which is why rolling is easier than sliding.
- Q6Easy
The friction experienced by an object moving through air or water is called:
A.Rolling frictionB.Fluid friction (drag)✓ CorrectC.Static frictionD.Sliding frictionAnswer: B. Fluid friction (drag)
Explanation: Fluids (liquids and gases) exert fluid friction, also called drag, on objects moving through them.
- Q7Medium
Even surfaces that look smooth still produce friction because:
A.They are colouredB.They have tiny irregularities visible only under a microscope✓ CorrectC.They are magneticD.They are heavyAnswer: B. They have tiny irregularities visible only under a microscope
Explanation: No surface is perfectly smooth; microscopic bumps interlock to cause friction.
- Q8Medium
Why is it harder to walk on a smooth, wet, marble floor than on a dry rough floor?
A.Marble is heavierB.Marble is magneticC.There is no gravity on marbleD.The smooth wet surface offers less friction, so the feet slip✓ CorrectAnswer: D. The smooth wet surface offers less friction, so the feet slip
Explanation: Less friction on a smooth, wet surface means the feet cannot grip, so we slip.
- Q9Medium
Why is friction called a 'necessary evil'?
A.It is always harmfulB.It is needed for walking, writing and braking, but it also wears out parts and wastes energy✓ CorrectC.It is always usefulD.It has no use at allAnswer: B. It is needed for walking, writing and braking, but it also wears out parts and wastes energy
Explanation: Friction is essential for everyday tasks, yet it also causes wear and heat loss — a necessary evil.
- Q10Medium
How does oil reduce friction between two metal parts?
A.It fills the irregularities and forms a thin layer that keeps the surfaces slightly apart✓ CorrectB.It makes the parts magneticC.It increases the roughnessD.It heats the partsAnswer: A. It fills the irregularities and forms a thin layer that keeps the surfaces slightly apart
Explanation: The oil layer separates the surfaces and smooths the irregularities, lowering friction.
- Q11Medium
Why is more force needed to start moving a box than to keep it moving?
A.The box gets heavierB.The floor meltsC.Static friction (at the start) is greater than sliding friction (while moving)✓ CorrectD.Gravity changesAnswer: C. Static friction (at the start) is greater than sliding friction (while moving)
Explanation: Static friction must be overcome to start motion and is larger than the sliding friction during motion.
- Q12Hard
Two perfectly polished steel blocks still show some friction. This proves that:
A.Polishing creates frictionB.No real surface is perfectly smooth; microscopic irregularities remain✓ CorrectC.Steel is magneticD.Friction needs colourAnswer: B. No real surface is perfectly smooth; microscopic irregularities remain
Explanation: Even polished surfaces have microscopic bumps, so some friction always remains.
- Q13Hard
On the same surface, an empty box needs 10 N to slide and the same box loaded needs 25 N. This is mainly because loading:
A.Changes the colourB.Reduces frictionC.Makes the box magneticD.Increases the force pressing the surfaces together, so friction increases✓ CorrectAnswer: D. Increases the force pressing the surfaces together, so friction increases
Explanation: Heavier load presses the surfaces harder, increasing friction and the force needed to slide it.
- Q14Hard
Which statement BEST captures why friction is a 'necessary evil'?
A.It is only harmfulB.We could not walk, write or stop vehicles without it, yet it also wears parts and wastes energy as heat✓ CorrectC.It is only usefulD.It has no effect either wayAnswer: B. We could not walk, write or stop vehicles without it, yet it also wears parts and wastes energy as heat
Explanation: Friction is indispensable for daily life but simultaneously causes wear and energy loss — necessary yet evil.
Start this chapter free
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Start this chapter free →Friction — FAQs
What are the key concepts in Class 8 Science Friction?+
This chapter covers friction — its causes, types, advantages and disadvantages, and ways to increase or reduce it. Key ideas include Friction, Cause of friction, Types of friction, Advantages & disadvantages.
What does Class 8 Science Chapter 109 (Friction) cover on XamBaaz?+
It has 72 NCERT-based MCQs on "Friction": 24 Easy, 24 Medium and 24 Hard. Together they make 6 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE Board exams.
Are these "Friction" questions free to practise?+
Yes. Sign in with Google to practise "Friction" free. Full unlimited access is ₹999/year on a launch offer until 1 December 2026. No chapter is charged separately.
How should I revise "Friction" for the exam?+
Start with the Easy quiz to check your basics, then try Medium and Hard to practise applying them. There are 6 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "Friction" MCQs available with answers?+
Yes. 14 sample questions are shown here in full, each with the correct option and a step-by-step "Why" explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "Friction" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from Friction (Class 8 Science)?+
The questions that matter most test Friction, Cause of friction, Types of friction, Advantages & disadvantages. This page shows 14 solved important MCQs with answers and explanations; all 72 questions on the chapter are available as timed quizzes once you sign in.
Is there an online quiz for Friction?+
Yes — Class 8 Science Friction has timed online quizzes at Easy, Medium and Hard levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.