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प्रश्न
Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play
पर्याय
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.
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उत्तर
irrespective of whether the objects are solid, liquid or gaseous.
Explanation:
Force of friction acts in solids, liquids and gases and opposes the motion with respect to each other.
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संबंधित प्रश्न
A charged glass rod attracts a charged plastic straw.
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The sliding friction is more than the rolling friction.
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Define static friction
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More the roughness of a surface, greater is the ........................
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Sliding friction and rolling friction are types of .................. friction.
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Friction always
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Rolling friction is ........... than sliding friction.
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Smoother the surface, ................. is the frictional force offered by it.
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Friction depends upon the ............... of an object.
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Friction has no relation with our walking or running.
Answer the following in a word or two or in a sentence.
Why is difficult for a pen to leave a mark on a highly smooth plastic sheet?
Answer the following in short.
Define rolling friction and give an example where rolling. friction comes into play.
Answer the following in short.
How can sliding friction be changed into rolling friction easily?
Rolling friction is slightly greater than sliding friction.
Match the following.
| Column I | Column II | |
| a) | Static friction | viscosity |
| b) | Kinetic friction | least friction |
| c) | Rolling friction | objects are in motion |
| d) | Friction between the liquid layers | objects are sliding |
| e) | Sliding friction | objects are at rest |
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.
Assertion: We can live very happily if friction is not present in nature.
Reason: The airplane shape is streamlined to reduce the effort of frictional force.
