CBSE Science Class 8

Friction

Friction - Chapter Wise CBSE Solved Question and Answer Based On NCERT

Short Q&A:

Q1: Why a vehicle slows down when brakes are applied?
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Q2: Why it is difficult to move on wet floor?
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Q3: Define force of friction with an example.
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Q4: What are the factors affecting friction?
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Q5: Give an example to show that friction increases if the two surfaces are pressed harder.
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Q6: Why sliding friction is slightly smaller than static friction?
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Q7: What would have happened if there were no friction between chalk and board?
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Q8: When we strike a matchstick against the rough surface, it produces fire. Why so?
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Q9: Give an example to support that friction leads to wastage of energy.
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Q10: How can we increase friction of soles of shoes?
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Q11: How can we increase friction of tyres of vehicles?
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Q12: Give an example where we have to minimise friction.
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Q13: What is the function of lubricants?
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Q14: Why friction can never be entirely eliminated?
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Q15: What is rolling friction?
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Q16: Why it is convenient to pull luggage bags fitted with rollers?
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Q17: What do you mean by sliding friction?
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Q18: Differentiate between sliding and rolling friction.
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Q19: Define fluid friction.
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Q20: How frictions are reduced in machines?
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Q21: How can we reduce fluid friction?
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Q22: Explain why sportsmen use shoes with spikes.
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Q23: A has to push a lighter box and B has to push same heavier box on the same floor, who will have to apply larger force and why?
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Q24: Why objects moving in fluid must have special shapes.
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Q25: Why it is difficult to walk on a floor wet with soapy water?
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Q26: Why it is difficult to walk on an extra smooth floor?
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Q27: Explain the function of spring balance.
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Q28: What is lubricated friction?
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Q29: What are the factors effecting friction?
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Q30: “Friction is an evil too”. Justify the statement.
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Chapter 12 Friction