Wednesday, 24 February 2021

CBSE Class 8 Science - MCQ and Online Tests - Unit 12 - Friction

CBSE Class 8 Science – MCQ and Online Tests –  Unit 12 – Friction

Every year CBSE students attend Annual Assessment exams for 6,7,8,9,11th standards. These exams are very competitive to all the students. So our website provides online tests for all the 6,7,8,9,11th standards’ subjects. These tests are also very effective and useful for those who preparing for any competitive exams like Olympiad etc. It can boost their preparation level and confidence level by attempting these chapter wise online tests.

These online tests are based on latest CBSE syllabus. While attempting these, our students can identify their weak lessons and continuously practice those lessons for attaining high marks. It also helps to revise the NCERT textbooks thoroughly


 

CBSE Class 8 Science – MCQ and Online Tests – Unit 12 – Friction

Choose the correct option.

Question 1.
Friction due to fluids is called
(a) force
(b) pressure
(c) friction
(d) drag

Answer

Answer: (d) drag


Question 2.
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

Answer

Answer: (b) polished marble surface


Question 3.
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

Answer

Answer: (b) Surface of tyres


Question 4.
Static friction is less than
(a) sliding friction
(b) rolling friction
(c) both (a) and (b)
(d) none of these

Answer

Answer: (d) none of these


Question 5.
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.

Answer

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


Question 6.
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

Answer

Answer: (a) Stone


Question 7.
The shape of an aeroplane is like a
(a) dog
(b) bird
(c) car
(d) all of these

Answer

Answer: (b) bird


Question 8.
Friction is
(a) foe
(b) friend
(c) both (a) and (b)
(d) none of these

Answer

Answer: (c) both (a) and (b)


Question 9.
A boat or an aeroplane has a pointed or tapering front / head. Why?
(a) To increase the friction of fluid
(b) To reduce the friction of fluid
(c) To look good
(d) For no reason

Answer

Answer: (b) To reduce the friction of fluid


Question 10.
The sole of the shoes becomes plain after wearing it for several months. The reason is
(a) Wearing out due to friction
(b) Wearing out due to no friction
(c) Sole is of bad quality
(d) None of the above

Answer

Answer: (a) Wearing out due to friction


Question 11.
Friction is a
(a) non-contact force
(b) contact force
(c) magnetic force
(d) electrostatic force

Answer

Answer: (b) contact force


Question 12.
Which of the following produces least friction?
(a) Sliding friction
(b) Rolling friction
(c) Composite friction
(d) Static friction

Answer

Answer: (b) Rolling friction


Question 13.
If we apply oil on door hinges, the friction will
(a) increase
(b) decrease
(c) disappear altogether
(d) will remain unchanged

Answer

Answer: (b) decrease


Question 14.
Lubricant
(a) reduce friction
(b) increase friction
(c) both (a) and (b)
(d) none of these

Answer

Answer: (a) reduce friction


Question 15.
Force of friction depends on
(a) roughness of surface
(b) smoothness of surface
(c) inclination of surface
(d) all of these

Answer

Answer: (d) all of these


Question 16.
Force of friction depends on
(a) roughness of surface
(b) weight
(c) size
(d) all of these

Answer

Answer: (d) all of these


Question 17.
Fluids are
(a) liquids
(b) gases
(c) both (a) and (b)
(d) none of these

Answer

Answer: (c) both (a) and (b)


Question 18.
Which is a streamlined object?
(a) Boats
(b) Aeroplanes
(c) Ships
(d) All of these

Answer

Answer: (d) All of these


Question 19.
Smooth surface has
(a) less friction
(b) more friction
(c) sometimes less and sometimes more
(d) all of these

Answer

Answer: (a) less friction


Question 20.
Which of the following is responsible for wearing out of bicycle tyres?
(a) Muscular force
(b) Magnetic force
(c) Frictional force
(d) Electrostatic force

Answer

Answer: (c) Frictional force


Question 21.
It is difficult to walk on an oily floor because
(a) Floor gets spoiled
(b) There is more resistance
(c) Force of friction is high
(d) Force of friction is very less

Answer

Answer: (d) Force of friction is very less


Question 22.
Spring balance is a device used for measuring the _____________ acting on an object.
(a) mass
(b) pressure
(c) force
(d) None of the above

Answer

Answer: (c) force


Question 23.
A matchstick struck on a matchbox catches fire easily because
(a) Friction may cause fire
(b) Of chemical reaction
(c) Force heated the match stick
(d) None of the above

Answer

Answer: (a) Friction may cause fire


Question 24.
Tyres are treaded to
(a) look good
(b) Increase friction
(c) increase its longivity
(d) increase weight of the tyre

Answer

Answer: (b) Increase friction


Question 25.
Lubricants are substances which
(a) Increase friction
(b) Are used to light fire
(c) Reduce friction
(d) Are used to put out a fire

Answer

Answer: (c) Reduce friction


Question 26.
Sliding friction is _________ than / to rolling friction
(a) smaller
(b) greater
(c) equal
(d) None of the above

Answer

Answer: (b) greater


Question 27.
The frictional force exerted by fluids is also called ______
(a) drug
(b) drag
(c) drop
(d) drown

Answer

Answer: (b) drag


Question 28.
Four children were asked to arrange forces due to rolling, static and sliding frictions in an increasing order. Their arrangements are given below. Choose the correct arrangement.
(a) Rolling, Static, Sliding
(b) Static, Rolling, Sliding
(c) Rolling, sliding, static
(d) Sliding, Static, Rolling

Answer

Answer: (c) Rolling, sliding, static


Question 29.
Friction always
(a) opposes the motion
(b) helps the motion
(c) both (a) and (b)
(d) none of these

Answer

Answer: (a) opposes the motion


Question 30 .
Friction can be reduced by using
(a) oil
(b) grease
(c) powder
(d) all of these

Answer

Answer: (d) all of these


Share:

0 comments:

Post a Comment

In Article

Definition List

Unordered List

Support