lass 8 Science MCQ Questions of Friction with Answers for a significant piece of exam for Class 8 Science and whenever practiced appropriately can assist you with getting better grades. Refer to more Chapter-wise MCQ Questions for Class 8 Science and furthermore check out more most recent study material for all subjects.

MCQ Questions for Class 8 Science with Answers were arranged dependent on the most recent Exam Pattern, Syllabus, NCERT curriculum. We have given MCQ Questions to Class 8 with answers to assist understudies with understanding the idea well indeed. These MCQ Questions for Class 8 Friction will allow students a chance to test their knowledge and also prepare for the examination.

Practice Class 8 Science MCQ Questions chapter-wise

1. Friction is a

(a) non-contact force
(b) contact force
(c) magnetic force
(d) electrostatic force

2. Which of the following produces the least friction?

(a) Sliding friction
(b) Rolling friction
(c) Composite friction
(d) Static friction

3. Friction always

(a) opposes the motion
(b) helps the motion
(c) both (a) and (b)
(d) none of these

4. Friction can be reduced by using

(a) oil
(b) grease
(c) powder
(d) all of these

5. Static friction is less than

(a) sliding friction
(b) rolling friction
(c) both (a) and (b)
(d) none of these

6. Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play

(a) only if the objects are solid.
(b) only if one of the two objects is liquid.
(c) only if one of the two objects is gaseous.
(d) irrespective of whether the objects are solid, liquid or gaseous

7. To sharpen the blade of a knife by rubbing it against a surface, which of the following will be most suitable?

(a) Stone
(b) Plastic block
(c) Wooden block
(d) Glass block

8. The shape of an aeroplane is like a

(a) dog
(b) bird
(c) car
(d) all of these

9. Friction due to fluids is called

(a) force
(b) pressure
(c) friction
(d) drag

10. Which of the following is not a smooth surface?

(a) Surface of wet soap
(b) Surface of tyres
(c) Glazed tiles
(d) Surface of mirror

11. A toy car released with the same initial speed will travel farthest on

(a) muddy surface
(b) polished marble surface
(c) cemented surface
(d) brick surface

12. If we apply oil on door hinges, the friction will

(a) increase
(b) decrease
(c) disappear altogether
(d) will remain unchanged

13. Lubricant can

(a) reduce friction
(b) increase friction
(c) both (a) and (b)
(d) none of these

14. Force of friction depends on

(a) roughness of surface
(b) smoothness of surface
(c) inclination of surface
(d) all of these

15. Which is a streamlined object?

(a) Boats
(b) Aeroplanes
(c) Ships
(d) All of these

16. Smooth surface has

(a) less friction
(b) more friction
(c) sometimes less and sometimes more
(d) all of these

17. Which of the following is responsible for wearing out of bicycle tyres?

(a) Muscular force
(b) Magnetic force
(c) Frictional force
(d) Electrostatic force

18. Tyres are treaded to

(a) look good
(b) Increase friction
(c) increase its longivity
(d) increase weight of the tyre

19. Four children were asked to arrange forces due to rolling, static and sliding frictions in decreasing order. Their arrangements are given below.
Choose the correct arrangement.

(a) Rolling, static, sliding
(b) Rolling, sliding, static
(c) Static, sliding, rolling
(d) Sliding, static, rolling

20. A matchstick catches fire when struck against the side of the matchbox because:

(a) of the chemicals
(b ) of friction
(c) friction produces a spark and the
(d) none of these chemicals catches fire

21. Talcum powder should not be spilled on the floor of the room because:

(a) it will stain the floor
(b) it may cause us to slip and fall
(c) it is messy
(d) none of these

22. Gymnasts apply some coarse substance on their hands to:

(a) increase friction for better grip
(b) decrease friction
(c) play fast
(d) none of these

23. Ball-bearing are used to reduce friction by

(a) Applying lubricants to the balls used
(b) Increasing the area of contact with the use of metallic balls
(c) Reducing the area of contact with the use of metallic balls
(d) None of the above

24. To convert the static, sliding friction into rolling friction, the heavy luggage carriers are attached at their base.

(a) ball-bearings
(b) chains
(c) tyres
(d) wheels

25. Friction produces

(a) Motion
(b) Force
(c) Heat
(d) Light

Answer:

1. Answer: (b) contact force

Explanation: Friction is a contact force because the bodies need to get in contact with each other in order for the frictional force to act on the bodies.

2. Answer: (b) Rolling friction

Explanation: Rolling friction produces the least friction.

3. Answer: (a) opposes the motion

Explanation: Frictional force acts between two surfaces in contact. It stops the object from moving as the irregularities on both the surface lock into each other, thus obstructing any forward motion. Hence, frictional force always opposes the applied force.

4. Answer: (d) all of these

Explanation: Friction can be described as an opposing force that resists other forces such as rolling, sliding.Friction can be reduced by adding lubricants such as grease, oil or powder.Polishing surfaces can also reduce friction.Friction is the leading cause of surface roughness.

5. Answer: (d) none of these

Explanation: Static friction is strongest, followed by sliding friction, and then rolling friction, which is weakest.

6. Answer: (d) irrespective of whether the objects are solid, liquid or gaseous

Explanation: Friction occurs irrespective of state of the matter. Friction provided by liquids and gases are known as fluid friction.

7. Answer: (a) Stone

Explanation: Stone will be more suitable because it will exert greater reaction and hence greater friction force which sharpen the blade of a knife easily by rubbing.

8. Answer: (b) bird

Explanation: Aeroplanes have been designed as birds. Birds have a light body, shaped such as to have a minimum wind resistance when they fly to overcome the friction. Thus, aeroplanes have been designed such as to have a streamlined body to overcome the frictional force of air.

9. Answer: (d) drag

Explanation: This frictional force is called drag force, and this parallels the motion of the body in a fluid medium. Hence option D is the correct answer and as per this frictional force exerted by fluids is called drag.

10. Answer: (b) Surface of tyres

Explanation: As we know that the surface of tyres is rough and uneven so we can say that the surface of a tyre is not a smooth surface.

11. Answer: (b) polished marble surface

Explanation: Because a polished marble floor has the least frictional force and inertia, a car will move farthest on it.

12. Answer: (b) decrease

Explanation: When we put the oil the rough interlocks between the surface and body are filled by the drops of oil and hence become smooth and then the friction decreases. So, here we can say that if we apply oil on door hinges, the friction will decrease.

13. Answer: (a) reduce friction

Explanation: Lubricants are substances which reduce friction.

14. Answer: (d) all of these

Explanation: Friction depends partly on the smoothness of the contacting surfaces, a greater force being needed to move two surfaces past one another if they are rough than if they are smooth.

15. Answer: (d) all of these

Explanation: Streamlined objects would include objects that are designed to travel quickly and create a minimum of friction against either air or water. Some objects that are streamlined include trains, airplanes, space shuttles, rockets, boats, submarines, racing cars, racing boats, and even televisions.

16. Answer: (a) less friction

Explanation: Friction is less on a smooth surface, hence the roller travels a greater distance on a smooth surface compared with the rough surface

17. Answer: (c) Frictional force

Explanation: Frictional force is responsible for wearing out of bicycle tyres.

18. Answer: (b) Increase friction

Explanation: The tyres of cars, trucks and bulldozers have treads or grooves in the rubber which is designed to allow water to be expelled from beneath the tire. This provides better grip with the ground thereby increasing friction for better handling.

19. Answer: (c) Static, sliding, rolling

Explanation: Sliding friction is the force of friction, below two objects when one of them is sliding over the surface of the other. The force of sliding friction between them is a little smaller than static friction between them. Between the same two surfaces, once motion is started the friction becomes slightly less than maximum static force rolling friction - a force of friction that comes into play when one body rolls over the surface of another body.It is more convenient to roll then to slide an object once the surface of other Hence, static friction > sliding friction > Rolling friction.

20. Answer: (c) friction produces a spark and the

Explanation: A matchstick catches fire when struck against the side of the matchbox because friction produces a spark and the chemicals catch fire.

21. Answer: (b) it may cause us to slip and fall

Explanation: Friction is a force that only occurs when an object moves. Talcum powder should not be spilled on the floor of room because it may cause us to slip and fall.

22. Answer: (a) increase friction for better grip

Explanation: Gymnasts apply the coarse substance on their hands to increase friction for a better grip. The coarse substance is chalk powder. The powder increases the friction between the bar and the gymnast's hands. It also absorbs sweat from the hands and keeps it dry for a better grip.

23. Answer: (c) Reducing the area of contact with the use of metallic balls

Explanation: Ball bearing reduce friction by using smooth balls lubricated with oil or grease that freely roll between a smooth inner and outer surface. The area of contact between the inner and outer surface decreases hence friction decreases between them.

24. Answer: (d) wheels

Explanation: To convert the static, sliding friction into rolling friction, the heavy luggage carriers are attached with wheels at their base, wheels decrease the friction. The decreasing order is static, sliding, and rolling

25. Answer: (c) Heat

Explanation: Friction always slows a moving object down. The amount of friction depends on the materials from which the two surfaces are made. The rougher the surface, the more friction is produced. Friction also produces heat

Click here Practice MCQ Question for Friction Class 8