[PDF] Extra Questions for Class 8 Science Chapter 12 Friction
Here we are providing extra questions for CBSE Class 8 Science Chapter 12 Friction. In the pursuit of a comprehensive understanding of CBSE Class 8 Science Chapter 12 “Friction,” practicing extra questions emerges as a valuable strategy. Students are suggested to go through each and every question for better concept coverage.
Table of Contents
Very Short Answer Type Questions
Q.1 What is force of friction?
Ans. The force acting on a moving body which is equal and opposite to the direction of motion is called force of friction.
Q.2 What is the direction of frictional force?
Ans. The direction of frictional force is opposite to the relative motion between the surfaces.
Q.3 How many types of friction are there?
Ans. There are four types of friction:
(i) Static friction
(ii) Sliding friction.
(iii) Rolling friction
(iv) Limiting friction
Q.4 Which is less sliding friction or static friction?
Ans. Sliding friction is smaller than the static friction.
Q.5 Why is it difficult to move on a wet marble floor?
Ans. Wet marble floor has less friction, so it is difficult to move on it.
Q.6 Why does a matchstick catch fire when it is rubbed on a rough surface?
Ans. Matchstick catches fire due to heat developed by friction.
Q.7 Write one harm of friction.
Ans. Friction wears out the materials like machine parts.
Q.8 Why do the tyres of cars and trucks are treaded?
Ans. The treaded tyres of cars and trucks provide better grip with the ground.
Q.9 What do you mean by lubricants?
Ans. The substances which are used to reduce friction are called lubricants.
Q.10 Can we eliminate friction completely?
Ans. No, we cannot eliminate friction completely.
Q.11 What is used to reduce friction in machines where lubrication are not advisable?
Ans. Air cushion.
Q.12 Name two methods of reducing friction.
Ans. (i) By rolling
(ii) Lubricating.
Q.13 What is drag?
Ans. The frictional force exerted by fluids is called drag.
Q.14 What are fluids?
Ans. Commonly gases and liquids are called fluids.
Q.15 What does frictional force exerted on an object in a fluid depend on?
Ans. Friction depends on the speed with respect to the fluid, the nature of fluid and the shape of the object.
Q.16 Name the special shape given to objects moving in fluid.
Ans. Streamlined shape.
Q.17 Name some examples which have streamlined body.
Ans. Boats, aeroplanes and ships.
Q.18 When does rolling friction come into play?
Ans. When a body rolls on other body then rolling friction come into play.
Q.19 What a spring balance measures?
Ans The magnitude of the force.
Q.20 Why we fall down when we step on a banana peel?
Ans. The banana peel reduces the friction between the feet and the road.
Significance of Practicing Extra Questions
The significance of practicing extra questions cannot be understated. These questions provide students with opportunities to revisit and apply the knowledge they’ve acquired from the chapter. As they engage with diverse problems, students sharpen their analytical thinking and enhance their ability to approach a range of scenarios related to force and pressure. Moreover, the act of solving extra questions cultivates a sense of confidence in tackling various exam formats and challenges.
