## Class 9 Science Objective Chapter – 10 Gravitation

Here we are providing Class 9 Science Objective Chapter – 10 Gravitation because its very important for Class 9 students as we all know that every board exam question has MCQs so that students should practice these questions so that students can get good marks in board. Class 9 Science Objective Chapter – 10 Gravitation is an extremely important and its also a year in which students learn the fundamentals of concepts that help them lay a solid foundation for their higher education. Here we are providing in Class Class 9 Science Objective Chapter – 10 Gravitation 100+ questions  so that students practice more and more. If you want class wise Notes Then Click Here

Class 9 Science Objective Chapter – 10 Gravitation

1.Two objects of different masses falling freely near the surface of the moon would

( A ) have same velocities at any instant

( B ) have different acceleration

( C ) experience forces of same magnitude

( D ) undergo a change in their inertia

Ans – ( A )

2. An apple and a stone dropped from certain height accelerates

( A ) equally

( B ) differently

( C ) depending on density

( D ) depends on the position of the Sun

Ans – ( A )

3. What is the mass per unit volume of a substance called?

( A ) Pressure

( B ) Force

( C ) Night

( D ) Density

Ans – ( D )

4. According to Archimedes’ principle when a body is submerged in a liquid, its apparent weight

( A ) decreases

( B ) increases

( C ) remains unchanged

( D ) may increase or decrease depending upon the material of the body

Ans – ( A )

5.The earth and the moon are attracted to each other by gravitational force. The earth attracts the moon with a force that is

( A ) More than that exerted by the moon

( B ) Same as that exerted by the moon

( C ) Less than that exerted by the moon

( D ) Not related to that exerted by the moon

Ans – ( B )

6.The unit of G in the S.I. system is

( A ) Newton m2/kg2

( B ) Newton m2 kg2

( C ) Newton m kg

( D ) Newton m2/kg

Ans – ( A )

7. If upthrust U is equal to 1/4  the weight of the object in air, then the weight felt in the liquid is

( A ) 1/4W

( B ) 3/4W

( C ) 1/2W

( D ) 2 W

Ans – ( B )

8.The value of acceleration due to gravity

( A ) is same on equator and poles

( B ) is least on poles

( C ) is least on equator

( D ) increases from pole to equator

Ans – ( C )

9. A mass weighing W can float if the upthrust U is related as

( A ) U > W

( B ) U = W

( C ) U < W

( D ) U  W

Ans – ( A )

10.The gravitational constant is denoted by which symbol?

( A ) g

( B ) M

( C ) G

( D ) k

Ans – ( C )

11.The gravitational force between two objects is F. If masses of both objects are halved without changing the distance between them, then the gravitational force would become

( A ) F/4

( B ) F/2

( C ) F

( D ) 2F

Ans – ( A )

12. The pressure exerted by man on earth is minimum when he

( A ) sits

( B ) stands on one foot

( C ) stands on both feet

( D ) lies on ground

Ans – ( D )

13.The unit of weight in the S.I. system is

( A ) kg m2

( B ) Newton

( C ) ms-2

( D ) ms

Ans – ( B )

14. When a body floats in a liquid, its apparent weight is always

( A ) less than the weight of the body

( B ) more than the weight of the body

( C ) equal to the weight of the body

( D ) zero

Ans – ( D )

15.A boy is whirling a stone tied to a string in a horizontal circular path. If the string breaks, the stone

( A ) will continue to move in the circular path

( B ) will move along a straight line towards the centreof the circular path

( C ) will move along a straight line tangential to the circular path

( D ) will move along a straight line perpendicular to the circular path away from the boy

Ans – ( C )

16.When an object is released from a height, its initial velocity is

( A ) u = 100 ms-1

( B ) u = 9.8 ms-1

( C ) u = 0

( D ) u = 1/2

Ans – ( C )

17. Thrust exerted by an iron cuboid when placed on sand is equal to

( A ) mass of cuboid

( B ) mass per unit surface area

( C ) weight of cuboid

( D ) weight per unit surface area

Ans – ( C )

18.Choose the correct unit for the relative density among the following

( A ) kg/cm

( B ) unitless

( C ) kg/cm

( D ) kg/m3

Ans – ( B )

19.The mass of the earth is

( A ) 6.4 × 1024

( B ) 6 × 1010 kg

( C ) 6 × 1024 kg

( D ) 6 × 1019 kg

Ans – ( C )

20. The gravitational force between two bodies does not depend on

( A ) their separation

( B ) their masses

( C ) the product of their masses

( D ) the medium between the two bodies

Ans – ( D )

21.An object is put one by one in three liquids having different densities. The object floats with 19, 211 and 37 parts of their volumes outside the liquid surface in liquids of densities d1, d2 and d3respectively. Which of the following statement is correct?

( A ) d1 > d2 > d3

( B ) d1 > d2 < d3 ( C ) d1 < d2 > d3

( D ) d1 < d2 < d3

Ans – ( D )

22. When a body is weighed in a liquid, the loss in weight is equal to

( A ) weight of liquid displaced by the body

( B ) weight of water displaced by the body

( C ) weight of body in air

( D ) half the weight of body in air

Ans – ( A )

23.The radius of the earth is

( A ) 6.4 × 10-6 m

( B ) 6.4 × 106 m

( C ) 4.6 × 106 m

( D ) 6.4 × 104 m

Ans – ( B )

24.An object having mass equal to 350 g occupies 200 cm3 of the space. When this object is thrown into a river what will be the condition of this object there? (Density of water = 1 g/ cm3)

( A ) It will float on the surface of water

( B ) It will float fully submerged in the liquid

( C ) It will sink in the liquid

( D ) It will float partially submerged in the liquid

Ans – ( A )

25. The weight of an object is least at some region of the earth. What will be the colour of bears found in that region.

( A ) black

( B ) white

( C ) blue

( D ) brown

Ans – ( B )

26.By applying the universal law of gravitation, the weight of the object on the moon will be

( A ) Wm=GR2m/Mm×m

( B ) Wm=GMm×R2m/m

( C ) Wm=GR2m×m/Mm

( D ) Wm=GMm×mR2m

Ans – ( D )

27.In the relation F = GM mld2, the quantity G

( A ) depends on the value ofg at the place of observation

( B ) is used only when the Earth is one of the two masses

( C ) is greatest at the surface of the Earth

( D ) is universal constant of nature

Ans – ( D )

28. The relative density of a solid is 0.6. It floats in water with

( A ) 40% of its volume inside water

( B ) 60% of its volume inside water

( C ) whole of its volume inside water

( D ) any fraction of its volume inside water

Ans – ( B )

29.The value of acceleration due to gravity

( A ) is the same on the equator and poles

( B ) is least on poles

( C ) is least on the equator

( D ) increases from pole to equator

Ans – ( C )

30. Two particles are placed at some distance. If the mass of each of the two particles is doubled, keeping the distance between them unchanged, the value of gravitational force between them will be

( A ) 1/4 times

( B ) 4 times

( C ) 1/2 times

( D ) unchanged

Ans – ( B )

31.Law of gravitation gives the gravitational force between

( A ) the Earth and a point mass only

( B ) the Earth and Sun only

( C ) any two bodies having some mass

( D ) two charged bodies only

Ans – ( C )

32. An empty closed drum and a filled drum of same dimension will bring

( A ) same upthrust

( B ) same volume

( C ) both ( A ) and (b)

( D ) neither ( A ) nor (b)

Ans – ( C )

33.The value of quantity G in the law of gravitation

( A ) depends on the mass of earth only

( B ) depends on the radius of the earth only

( C ) depends on both the mass and radius of the earth

( D ) is independent of the mass and radius of the earth

Ans – ( D )

34. What is buoyant force-

( A ) An upward force on an object immersed in a liquid

( B ) Partially downward force

( C ) A down ward force on an object immersed in a liquid

( D ) None of the above.

Ans – ( A )

35.The school bags are generally provided with the broad strips because

( A ) It will spread the force of the bag over the large area of the shoulder of the child producing large pressure

( B ) It will spread the force of the bag over the large area of the shoulder of the child producing less pressure

( C ) It has become a trend among the students to carry the bags with wide strips

( D ) It will spread the force of the bag over the small area of the shoulder of the child producing less pressure

Ans – ( B )

36.The atmosphere is held to the earth by

( A ) gravity

( B ) wind

( C ) clouds

( D ) earth’s magnetic field

Ans – ( A )

37.The value of quantity G in the law of gravitation

( A ) depends on mass of Earth only

( B ) depends on radius of Earth only

( C ) depends on both mass and radius of Earth

( D ) is independent of mass and radius of the Earth

Ans – ( D )

38.Law of gravitation gives the gravitational force between

( A ) the earth and a point mass only

( B ) the earth and sun only

( C ) any two bodies having some mass

( D ) two charged bodies only

Ans – ( C )

39.Two particles are placed at some distance. If the mass of each of the two particles is doubled, keeping the distance between them unchanged, the value of gravitational force between them will be

( A ) 14 times

( B ) 4 times

( C ) 12 times

( D ) unchanged

Ans – ( B )

40. According to first law of motion, the states of uniform motion and rest are ……

( A ) Equal

( B ) Unequal

( C ) Non related

( D ) None of these.

Ans – ( A )

41. The value of acceleration due to gravity on the surface of the earth at sea level is

( A ) 4.9 m/s2

( B ) 6 m/s2

( C ) 8 m/s2

( D ) 9.8 m/s2

Ans – ( D )

42. Force is a physical quantity depends on

( A ) Speed

( B ) Mass

( C ) Acceleration

( D ) Both b and c

Ans – ( D )

43.The atmosphere is held to the Earth by

( A ) gravity

( B ) wind

( C ) clouds

( D ) Earth’s magnetic field

Ans – ( A )

44. If a particles of mass 8 kg is moving with constant velocity of 20 m/s then net force on that object will be.

( A ) 160 N

( B ) 20 N

( C ) 80 N

( D ) 0 N

Ans – ( D )

45.The force of attraction between two unit point masses separated by a unit distance is called

( A ) gravitational potential

( B ) acceleration due to gravity

( C ) gravitational field

( D ) universal gravitational constant

Ans – ( D )

46. If a ball of mass 200 gm is moving with 20 m/s then its momentum is

( A ) 40 kg m/s

( B ) 400 kg m/s

( C ) 4 Kg m/s

( D ) 0.4 kg m/s

Ans – ( C )

47.The weight of an object at the centre of the Earth of radius R is (NCERT Exemplar)

( A ) zero

( B ) infinite

( C ) R times the weight at the surface of the Earth

( D ) 1/R2 times the weight at surface of the Earth

Ans – ( A )

48. The SI unit of g is

( A ) N m/kg

( B ) N m²/kg

( C ) N m² /kg²

( D ) N² m² / kg²

Ans – ( C )

49.An object weighs 10 N in air. When immersed fully in water, it weighs only 8 N. The weight of the liquid displaced by the object will be

( A ) 2 N

( B ) 8 N

( C ) 10 N

( D ) 12 N

Ans – ( A )

50.A girl stands on a box having 60 cm length, 40 cm breadth and 20 cm width in three ways. In which of the following cases, pressure exerted by the box will be

( A ) maximum when length and breadth form the base

( B ) maximum when breadth and width form the base

( C ) maximum when width and length form the base

( D ) the same in all the above three cases

Ans – ( B )

51. If a ball has mass 60 kg on earth then it’s mass on moon will be…

( A ) 10 kg

( B ) 40 kg

( C ) 0 kg

( D ) 60 kg

Ans – ( D )

52.The force which keeps the body to move in circular motion when accelerated is

( A ) Centripetal force

( B ) Magnetic force

( C ) Electrostatic force

( D ) Force of gravitation

Ans – ( A )

53. Magnitude of force in action and reaction is

( A ) Always equal

( B ) Always unequal

( C ) May be equal or unequal.

( D ) Depend on time of reaction.

Ans – ( A )

54.An apple falls from a tree because of gravitational attractionbetween the Earth and the apple. If F1 is the magnitude of force exerted by the Earth on the apple and F2 is the magnitude of force exerted by the apple on the Earth, then

( A ) F1 is very much greater than F2

( B ) F2 is very much greater than F1

( C ) F1 is only a little greater than F2

( D ) F1 and F1 are equal

Ans – ( D )