Friction
| Description: Friction | |
| Number of Questions: 15 | |
| Created by: Varsha Mane | |
| Tags: Science class 8 Integers Friction Friction, Factors Affecting Friction. Fluid Friction. |
Ball bearing is a device which converts
With reference to a horizontal moving object on a floor, in which direction does the force of friction act?
Which of the following statements is/are false? a. The force which always opposes the motion of one object over another object in contact with it is called friction. b. Friction acts on only one of the two surfaces in contact with each other. c. Friction is caused by the interlocking of irregularities in the surface of the two objects which are in contact with each other.
Which of the following is a device that is used for measuring force acting on an object?
What will be the most likely static friction between two surfaces A and B, if the sliding friction between them is 10 N?
Which of the following statements is/are false? a. A smaller block moves over a bigger block only when the pulling force applied becomes greater than the force of friction holding them together. b. In case of static friction, the object is not actually moving or sliding over the other object, it only tends to move or slide. c. Force of friction is lesser, if very rough surfaces are involved.
Which of the following statements is/are false? a. Friction can be increased by making the surfaces smooth by polishing. b. Friction can never be eliminated. c. The burning of matchstick is possible due to friction.
Which of the following is not a method to increase friction?
The substances which reduce friction are called lubricants. Which of the following cannot be used as a lubricant?
Which of the following statements is/are false? a. The frictional force exerted by a fluid is called drag force. b. Higher the speed of an object moving through a fluid, greater will be the frictional force. c. Drag force acts in a direction similar to the direction of the motion of the object.
If the rolling friction between two objects P and Q is 7 N, what will be their most likely sliding friction?
Match the following:
| a. Static friction | 1. It is the force resisting the motion when a body rolls on a surface. |
| b. Sliding friction | 2. It is the maximum force present between any two objects when one object just tends to move or slip over the surface of the other object. |
| c. Rolling friction | 3. It is the frictional force present when one object moves slowly over the surface of another object. |
The magnitude of frictional force exerted by a fluid on an object moving through it depends upon a. speed of the object b. shape of the object c. nature or viscosity of the fluid
Arrange the following types of friction in decreasing order of their strength? a. Sliding friction b. Rolling friction c. Static friction
Which of the following statements is/are false? a. There can be frictional force between two surfaces when there is no relative motion between the two. b. Higher the viscosity of fluid, greater will be the frictional force acting on an object moving through it. c. When objects move through fluids, they lose some of their energy in overcoming the fluid friction, decreasing their efficiency.