Chapter 2: Microorganisms : Friend and Foe
Chapter 3: Synthetic Fibres and Plastics
Chapter 4: Materials : Metals and Non-Metals
Chapter 5: Coal and Petroleum
Chapter 6: Combustion and Flame
Chapter 7: Conservation of Plants and Animals
Chapter 8: Cell—Structure and Functions
Chapter 9: Reproduction in Animals
Chapter 10: Reaching the Age of Adolescence
Chapter 11: Force
Chapter 12: Friction
Chapter 13: Sound
Chapter 14: Chemical Effects of Electric Current
Chapter 15: Some Natural Phenomena
Chapter 16: Light
Chapter 17: Stars and Solar System
Chapter 18: Pollution of Air and Water
Chapter 12: Friction
NCERT solutions for Science Exemplar Class 8 Chapter 12 Friction Multiple Choice Questions [Pages 68 - 69]
Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play
only if the objects are solid.
only if one of the two objects is liquid.
only if one of the two objects is gaseous.
irrespective of whether the objects are solid, liquid or gaseous.
In figure, a boy is shown pushing the box from right to left. The force of friction will act on the box
from right to left (←)
from left to right (→)
vertically downwards (↓)
vertically upwards (↑)
To sharpen the blade of a knife by rubbing it against a surface, which of the following will be most suitable?
A toy car released with the same initial speed will travel farthest on
polished marble surface
If we apply oil on door hinges, the friction will
will remain unchanged
Which of the following statements is incorrect?
Friction acts on a ball rolling along the ground
Friction acts on a boat moving on water
Friction acts on a bicycle moving on a smooth road
Friction does not act on a ball moving through air
A boy rolls a rubber ball on a wooden surface. The ball travels a short distance before coming to rest. To make the same, ball travel longer distance before coming to rest, he may
spread a carpet on the wooden surface
cover the ball with a piece of cloth
sprinkle talcum powder on the wooden surface
sprinkle sand on the wooden surface
In a large commercial complex there are four ways to reach the main road. One of the path has loose soil, the second is laid with polished marble, the third is laid with bricks and the fourth has gravel surface. It is raining heavily and Paheli wishes to reach the main road. The path on which she is least likely to slip is
NCERT solutions for Science Exemplar Class 8 Chapter 12 Friction Very Short Answer Questions [Pages 69 - 70]
Two blocks of iron of different masses are kept on a cemented floor as shown in the figure. Which one of them would require a larger force to move it from the rest position?
Will force of friction come into play when a rain drop rolls down a glass window pane?
Two boys are riding their bicycles on the same concrete road. One has new tyres on his bicycle while the other has tyres that are old and used. Which of them is more likely to slip while moving through a patch of the road which has lubricating oil spilled over it?
Figure shows two boys applying force on a box. If the magnitude of the force applied by each is equal, will the box experience any force of friction?
Imagine that an object is falling through a long straight glass tube held vertical, air has been removed completely from the tube. The object does not touch the walls of the tube. Will the object experience any force of friction?
NCERT solutions for Science Exemplar Class 8 Chapter 12 Friction Short Answer Questions [Pages 70 - 71]
You might have noticed that when used for a long time, slippers with rubber soles become slippery. Explain the reason.
Is there a force of friction between the wheels of a moving train and iron rails? If yes, name the type of friction. If an air cushion can be introduced between the wheel and the rail, what effect will it have on the friction?
Cartilage is present in the joints of our body which helps in their smooth movement. With advancing age, this cartilage wears off. How would this affect the movement of joints?
While playing tug of war, Preeti felt that the rope was slipping through her hands. Suggest a way out for her to prevent this.
The handle of a cricket bat or a badminton racquet is usually rough. Explain the reason.
Explain why the surface of mortar and pestle (silbatta) used for grinding is etched again after prolonged use.
A marble is allowed to roll down an inclined plane from a fixed height. At the foot of the inclined plane, it moves on a horizontal surface (a) covered with silk cloth (b) covered with a layer of sand and (c) covered with a glass sheet. On which surface, will the marble move the shortest distance. Give reason for your answer.
A father and son pushed their car to bring it to the side of road as it had stalled in the middle of the road. They experienced that although they had to push with all their might initially to move the car, the push required to keep the car rolling was smaller, once the car started rolling. Explain.
NCERT solutions for Science Exemplar Class 8 Chapter 12 Friction Long Answer Questions [Page 72]
When the cutting edge of a knife is put against a fast rotating stone to sharpen it, sparks are seen to fly. Explain the reason.
We have two identical metal sheets. One of them is rubbed with sand paper and the other with ordinary paper. The one rubbed with sand paper shines more than the other. Give reason.
While travelling on a rickshaw, you might have experienced that if the seat cover is very smooth, you tend to slip when brakes are applied suddenly. Explain.
Two friends are trying to push a heavy load as shown in the figure below. Suggest a way which will make this task easier for them.
Chapter 12: Friction
NCERT solutions for Science Exemplar Class 8 chapter 12 - Friction
NCERT solutions for Science Exemplar Class 8 chapter 12 (Friction) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the CBSE Science Exemplar Class 8 solutions in a manner that help students grasp basic concepts better and faster.
Further, we at Shaalaa.com provide such solutions so that students can prepare for written exams. NCERT textbook solutions can be a core help for self-study and acts as a perfect self-help guidance for students.
Concepts covered in Science Exemplar Class 8 chapter 12 Friction are Force of Friction, Effects of Friction, Increasing and Reducing Friction, Kinds of Friction, Fluid Friction, Friction - A Necessary Evil, Factors Affecting Friction.
Using NCERT Class 8 solutions Friction exercise by students are an easy way to prepare for the exams, as they involve solutions arranged chapter-wise also page wise. The questions involved in NCERT Solutions are important questions that can be asked in the final exam. Maximum students of CBSE Class 8 prefer NCERT Textbook Solutions to score more in exam.
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