Class 8 Science Chapter 12 MCQ for 2021-2022
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MCQ Tests with Answers for Class 8 Science Chapter 12
A boy runs his toy car on dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be:
[A]. Wet marble floor, Dry marble floor, Newspaper, Towel
[B]. Newspaper, Towel, Dry marble floor, Wet marble floor
[C]. Towel, Newspaper, Dry marble floor, Wet marble floor
[D]. Wet marble floor, Dry marble floor, Towel, Newspaper
Four children were asked to arrange forces due to rolling, static and sliding friction in a decreasing order. The correct arrangement is:
[A]. Rolling, Static, Sliding
[B]. Rolling, Sliding, Static
[C]. Static, Sliding, Rolling
[D]. Sliding, Static, Rolling
To sharpen the blade of a knife by rubbing it against a surface, which of the following will be most suitable?
[B]. Plastic block
[C]. Wooden block
[D]. Glass block
A big wooden box is being pushed on the ground from east to west direction. The force of friction due to ground will act on this box towards:
[A]. North direction
[B]. South direction
[C]. East direction
[D]. West direction
If we apply oil on door hinges, the friction will:
[A]. [A] Increase
[C]. Disappear Altogether
[D]. Will remain unchanged
The friction between two surfaces does not depend on one of the following. This one is:
[A]. Amount of surface area of the two objects which is in contact with each other
[B]. Weight of the object which tends to move on the surface of other object
[C]. Degree of smoothness of surfaces of two objects in contact with each other
[D]. Degree of roughness of surfaces of two objects in contact with each other
Which of the following statements is incorrect?
[A]. Friction acts on a ball rolling along the ground.
[B]. Friction acts on a boat moving on water
[C]. Friction acts on a bicycle moving on a smooth road.
[D]. Friction does not act on a ball moving through air.
If the sliding friction between two surfaces is found to be 8n, then the static friction between these two surfaces is most likely to be:
[A]. 5 N
[B]. 10 N
[C]. 4 N
[D]. 2 N
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:
[A]. Loose soil
[B]. Polished marble
If the static friction between two surfaces X and Y is found to be 20 N, then the rolling friction between these two surfaces should be most likely be:
[A]. 25 N
[B]. 20 N
[C]. 5 N
[D]. 50 N
If the static friction between two surfaces P and Q is measured to be 50 N, then the sliding friction between these two surfaces is most likely to be:
Which of the following statement is or are incorrect?
[A]. Friction can never be entirely eliminated.
[B]. Dolphins are streamlined body by nature to reduce friction with water.
[C]. The use of ball bearing makes the wheel roll smoothly over the axle.
[D]. None of the above.
Which of the following will produce the maximum friction?
[A]. Rubbing of sand paper on glazed paper
[B]. Rubbing of sand paper on glass table top
[C]. Rubbing of sand paper on aluminium frame
[D]. Rubbing of sand paper on sand paper
Four similar cars having exactly the same mass and running at the same speed on the same road when brakes are applied at the same time. The cars come to a stop after covering a distance of 5 m, 5.5 m, 4.8 m, and 5.2 m respectively. The friction between the brake pads and disc will be the maximum in car which travels the distance of:
[A]. 5 m
[B]. 5.5 m
[C]. 4.8 m
[D]. 5.2 m
Read the following sentences carefully, and choose the incorrect one:
[A]. Grooves are made in the soles of shoes to increase friction and prevent slipping.
[B]. Spikes are provided in the shoes of player and athletes to increase friction and prevent slipping.
[C]. Machines belts are made of special materials to increase friction and drive machines wheels properly.
[D]. None of the above.
Which of the following statement is or are correct?
[A]. We are able to walk on ground because friction between the sole of our shoes and ground prevents us from slipping over the ground.
[B]. Walking on slippery ground is difficult because the frictional force on slippery ground is much less which may not be sufficient to prevent us from sleeping.
[C]. When we accidentally step on a banana peel thrown on the road, we usually slip and fall down.
[D]. All the above.
A book is lying on the horizontal table top. If we till the table, then the book starts sliding down slowly. This happens because:
[A]. Sliding friction is greater than static friction
[B]. Sliding friction is less than force of gravity
[C]. Static friction is greater than sliding friction
[D]. Force of gravity is less than sliding friction
Consider the following statements and choose the incorrect one:
[A]. The burning of a matchstick would not be possible without friction.
[B]. We are able to cut wood because there is friction between the saw blade and log of wood.
[C]. We can hold a glass tumbler in our hands because of friction between the glass tumbler and our hands.
[D]. None of the above
Which of the following should be used to reduce friction on a carrom board?
[A]. A lubricating oil
[B]. A dry lubricant
[C]. A layer of grease
[D]. A ball bearing
In a quiz competition, you are asked a question where you have to choose the statement which is/ are incorrect?
[A]. Nails and screws are also held in wood by friction.
[B]. Friction enables knot to be tied in strings or ropes etc.
[C]. Friction enables a person to climb a tree or pole.
[D]. Friction does not help a ladder to be leaned against the wall.
A person has applied some mustard oil on his hands. Which of the following objects will become most difficult for him to hold in his hand?
[A]. Earthen cup (kulhar)
[B]. Thermocol tumbler
[C]. Glass tumbler
[D]. Wooden cup
Bikash is doing his homework which is given by his teacher. Would you help him to choose the correct sentences?
[A]. The pencil cell travels the least distance on the towel.
[B]. The pencil cell travels a larger distance on the wet marble floor.
[C]. The pencil cell travels less distance on the newspaper sheet then the dry marble floor.
[D]. All the above.
Consider the following statements and choose the correct one:
[A]. The fluid friction can be reduced or minimized by giving special shape called “streamlined shape”.
[B]. An aeroplane has a streamlined shape to reduces air friction that it encounters when flying at high speed through the sky.
[C]. The rockets are also built with streamlined shapes so that they encounter the minimum air resistance or drag due to air.
[D]. All the above.
Final examination in the last year, Rahul were asked a question where he had to choose the statement which was/were incorrect? Will you be able to answer this question?
[A]. When the oil is poured the marble floor, it decreases the irregularities.
[B]. When an object is pulled by a spring it decreases the friction.
[C]. Wrapping of polythene sheet makes the surface of bricks smooth due to which the friction with floor decreases
[D]. Wrapping of jute clothes make the surface of brick more-rough due to which the friction with floor decreases.
Ball bearing is a device which usually converts:
[A]. Rolling friction into sliding friction
[B]. Static friction into sliding friction
[C]. Sliding friction into rolling friction
[D]. Rolling friction into static friction
Why MCQs are important?
According to CBSE latest pattern of question papers, in every subject MCQ with four options will be asked. These MCQ help to revise the chapter as well as provide a perfect way for quick revision.