Chapter -1.5 "Forces" - MCQ's

 "Forces" - MCQ's

1. A force can change the size and shape of an object by

A. changing its color

B. rearranging its particles

C. destroying its mass

D. removing its weight

Answer: B

2. When a rubber band becomes longer after being pulled, this is an example of

A. compression

B. torsion

C. tension

D. friction

Answer: C

3. Which force reduces the length of an object?

A. Tension

B. Compression

C. Friction

D. Upthrust

Answer: B

4. A ruler placed across two supports bends when pressed in the middle. The top surface is under

A. tension

B. compression

C. torsion

D. friction

Answer: B

5. Twisting a metal wire is an example of

A. compression

B. bending

C. torsion

D. shear

Answer: C

6. Elastic deformation occurs when

A. the object breaks

B. the object permanently changes shape

C. the object returns to its original shape after the force is removed

D. the object melts

Answer: C

7. Plastic deformation occurs when

A. the object returns to original length

B. the object remains permanently stretched

C. the object vibrates

D. the object changes color

Answer: B

8. The elastic limit is the point where

A. the object starts to stretch

B. the object returns completely to its original shape

C. permanent deformation begins

D. the object breaks instantly

Answer: C

9. A long thin wire stretches more than a short thick wire because

A. it has more mass

B. its dimensions affect deformation

C. gravity is stronger

D. it is heavier

Answer: B

10. Car tyres deform where they touch the road mainly due to

A. friction only

B. magnetic force

C. the weight of the car

D. air resistance

Answer: C

🔹 Load–Extension Graphs – MCQs

11. In a load–extension graph, the load is usually plotted on the

A. horizontal axis

B. vertical axis

C. diagonal axis

D. curved axis

Answer: B

12. Extension is calculated by

A. stretched length + original length

B. original length − stretched length

C. stretched length − original length

D. mass × gravity

Answer: C

13. In the straight-line region of a load–extension graph

A. extension is not proportional to load

B. load is proportional to extension

C. load decreases

D. the object breaks

Answer: B

14. Hooke’s law states that

A. load is inversely proportional to extension

B. load equals mass × gravity

C. load is directly proportional to extension within the elastic limit

D. extension is constant

Answer: C

15. The gradient of a load–extension graph represents

A. mass

B. stiffness

C. density

D. volume

Answer: B

16. A steeper gradient on a load–extension graph indicates

A. a weaker material

B. a softer material

C. a stiffer material

D. plastic deformation

Answer: C

17. The limit of proportionality is the point where

A. the graph becomes curved

B. the object breaks

C. extension becomes zero

D. load decreases

Answer: A

18. If a spring is stretched beyond its elastic limit and then unloaded, it will

A. return exactly to original length

B. show permanent extension

C. shorten further

D. break immediately

Answer: B

19. Which precaution reduces parallax error in a load–extension experiment?

A. Using heavier masses

B. Reading at eye level

C. Removing the ruler

D. Increasing temperature

Answer: B

20. The load applied in experiments is calculated using

A. F = ma

B. F = mg

C. P = VI

D. W = Fd

Answer: B

21. Two forces of 8 N and 12 N act on an object in the same direction along a straight line. What is the resultant force?

A. 4 N

B. 20 N

C. 96 N

D. 12 N

Answer: B

22. Two forces act on an object along the same straight line: 18 N to the right and 11 N to the left. What is the resultant force?

A. 7 N to the right

B. 29 N to the right

C. 7 N to the left

D. 29 N to the left

Answer: A

23. An object has two forces acting on it: 25 N left and 25 N right. The object will

A. accelerate to the left

B. accelerate to the right

C. remain at rest or move at constant speed in a straight line

D. always slow down

Answer: C

24. Which statement best describes a zero resultant force?

A. No forces act on the object

B. Forces act but cancel out

C. The object must be stationary

D. The object must be accelerating

Answer: B

25. Three forces act along the same line: 10 N right, 6 N right, and 9 N left. What is the resultant force?

A. 5 N right

B. 7 N right

C. 25 N right

D. 13 N left

Answer: B

26. A car moves at constant speed in a straight line. This means the resultant force on the car is

A. maximum

B. zero

C. increasing

D. equal to its weight

Answer: B

27. Which situation definitely involves a non-zero resultant force?

A. A book resting on a table

B. A trolley moving at constant speed on a smooth track

C. A car speeding up in a straight line

D. A swimmer floating still in calm water

Answer: C

28. Newton’s First Law states that an object will remain at rest or move with constant velocity unless

A. gravity acts on it

B. friction is zero

C. a resultant force acts on it

D. its mass is large

Answer: C

29. Inertia is best described as

A. a force that opposes motion

B. the tendency of an object to resist change in motion

C. the speed of an object in a given direction

D. the mass multiplied by gravity

Answer: B

30. Which object has the greatest inertia?

A. A 0.5 kg football

B. A 2 kg bowling ball

C. A 20 kg suitcase

D. A 2000 kg truck

Answer: D

31. A bus stops suddenly and passengers move forward. This happens because passengers

A. are pushed forward by friction

B. have inertia and tend to keep moving

C. are pulled forward by gravity

D. have zero mass

Answer: B

32. An object continues moving at constant speed in a straight line. The forces on it are

A. unbalanced

B. balanced

C. increasing

D. acting at right angles

Answer: B

33. A cyclist continues at constant speed on a straight road. Which is true?

A. Driving force is greater than resistive forces

B. Driving force is less than resistive forces

C. Driving force equals resistive forces

D. No resistive forces act

Answer: C

34. A resultant force changes velocity by changing

A. only speed

B. only direction

C. speed and/or direction

D. mass only

Answer: C

35. A car moves around a corner at constant speed. Its velocity changes because

A. its speed decreases

B. its direction changes

C. friction becomes zero

D. its mass increases

Answer: B

36. In uniform circular motion, an object’s speed is constant but its velocity changes because

A. gravity stops acting

B. its direction keeps changing

C. there is no force acting

D. its mass changes

Answer: B

37. A force acting opposite to the direction of motion will

A. increase speed

B. decrease speed

C. change direction only

D. keep speed constant

Answer: B

38. A force acting at right angles to the motion will mainly

A. increase speed

B. decrease speed

C. change direction

D. stop the object instantly

Answer: C

39. A force acts at an angle to the direction of motion. This can

A. change only mass

B. change only temperature

C. change speed and direction

D. keep velocity constant

Answer: C

40. Which situation shows zero resultant force but the object is moving?

A. A car accelerating forward

B. A ball slowing down on grass

C. A puck gliding at constant speed on smooth ice

D. A stone falling freely

Answer: C

41. Solid friction is the force between two surfaces that

A. increases motion

B. opposes relative motion or attempted motion

C. acts only in liquids

D. acts only when there is no contact

Answer: B

42. When an object moves to the right across a table, the frictional force on the object acts

A. to the right

B. upward

C. to the left

D. downward

Answer: C

43. Friction produces heating because

A. energy is created

B. work done against friction becomes thermal energy

C. friction increases gravitational force

D. friction destroys kinetic energy completely

Answer: B

44. Which is an example of static friction?

A. A box sliding across the floor

B. A book resting on a table

C. A car moving through air

D. A stone sinking in water

Answer: B

45. Static friction acts when

A. surfaces are not touching

B. surfaces are touching but not moving relative to each other

C. surfaces are moving relative to each other

D. an object is moving in a circle

Answer: B

46. Which type of friction usually has a smaller value?

A. Maximum static friction

B. Kinetic (sliding) friction

C. Static friction at its maximum is always smaller

D. They are always equal

Answer: B

47. A book slides across a table and slows down. The main cause is

A. weight

B. upthrust

C. friction

D. tension

Answer: C

48. Which change would usually increase solid friction between two surfaces?

A. Lubricating the surfaces

B. Polishing the surfaces

C. Increasing the force pressing the surfaces together

D. Using ball bearings

Answer: C

49. Why do ball bearings reduce friction?

A. They increase surface roughness

B. They replace sliding friction with rolling friction

C. They increase weight

D. They decrease contact area to zero

Answer: B

50. Brakes in vehicles work mainly by

A. increasing upthrust

B. reducing mass

C. converting kinetic energy into heat by friction

D. converting heat into kinetic energy

Answer: C

Drag in Liquids

51. Drag in a liquid acts on an object

A. only when the object is stationary

B. only when the liquid is stationary

C. only when the object moves relative to the liquid

D. only when the object is rising

Answer: C

52. The drag force on an object moving through water acts

A. in the same direction as motion

B. opposite to the direction of motion

C. at right angles to motion always

D. downward only

Answer: B

53. Which factor will usually increase drag in a liquid?

A. Making the object more streamlined

B. Reducing surface area

C. Increasing speed

D. Polishing the object

Answer: C

54. An object moving through honey experiences more drag than through water because honey

A. has lower density

B. has higher viscosity

C. has lower viscosity

D. has no internal friction

Answer: B

55. Terminal velocity in a liquid is reached when

A. weight = drag only

B. drag = upthrust only

C. weight = drag + upthrust

D. upthrust = weight + drag

Answer: C

56. A ball falls through a liquid. As it speeds up, the drag force

A. decreases

B. stays constant

C. increases

D. becomes zero

Answer: C

57. When a falling object in a liquid reaches terminal velocity, its acceleration is

A. maximum

B. increasing

C. zero

D. negative and increasing

Answer: C

Drag in Gases (Air Resistance)

58. Air resistance is a force that

A. acts only on stationary objects

B. acts in the direction of motion

C. acts opposite to the direction of motion

D. removes gravity

Answer: C

59. Air resistance generally increases when

A. speed decreases

B. speed increases

C. mass increases only

D. weight decreases only

Answer: B

60. A parachute slows a skydiver mainly by

A. reducing the skydiver’s weight

B. increasing surface area, increasing air resistance

C. decreasing air resistance

D. increasing gravitational field strength

Answer: B

61. A sheet of paper falls slower than a crumpled ball of the same paper because the sheet has

A. greater mass

B. less air resistance

C. greater surface area and greater air resistance

D. less weight

Answer: C

62. At terminal velocity in air, the resultant force on a falling object is

A. equal to its weight

B. zero

C. maximum

D. equal to air resistance only

Answer: B

63. Which change will usually reduce air resistance on a moving car?

A. Increasing speed

B. Making the car less streamlined

C. Making the car more streamlined

D. Increasing surface area facing the airflow

Answer: C

64. Air resistance occurs mainly because

A. air has no particles

B. objects collide with air molecules and create pressure differences

C. gravity becomes stronger

D. air resistance depends only on mass

Answer: B

65. A cyclist crouches lower while riding fast mainly to

A. increase friction with the road

B. reduce air resistance

C. increase mass

D. reduce weight

Answer: B

66. The spring constant, k, is defined as

A. extension per unit force

B. force per unit extension

C. force × extension

D. extension − force

Answer: B

67. The unit of spring constant k is

A. N

B. m

C. N/m

D. m/N

Answer: C

68. A force of 12 N produces an extension of 0.06 m. What is the spring constant?

A. 0.005 N/m

B. 0.5 N/m

C. 200 N/m

D. 720 N/m

Answer: C

69. A spring has k = 300 N/m. What force is needed to produce an extension of 0.04 m?

A. 7.5 N

B. 12 N

C. 75 N

D. 1200 N

Answer: B

70. A spring has k = 500 N/m. A force of 15 N is applied. What is the extension?

A. 0.003 m

B. 0.03 m

C. 0.3 m

D. 30 m

Answer: B

71. Which equation is a correct rearrangement of 

Answer: C

72. A spring extends by 2.0 cm when a force of 4.0 N is applied. What is k?

A. 0.5 N/m

B. 2 N/m

C. 200 N/m

D. 400 N/m

Answer: D

73. A spring constant is large. This means the spring is

A. soft and easy to stretch

B. stiff and hard to stretch

C. made of rubber

D. beyond the limit of proportionality

Answer: B

74. On a force–extension graph (force on y-axis, extension on x-axis), the spring constant equals the

A. area under the graph

B. gradient of the straight-line part

C. intercept on the y-axis

D. maximum extension

Answer: B

75. A spring obeys Hooke’s law when its force–extension graph is

A. a curve through the origin

B. a straight line through the origin

C. a horizontal line

D. a straight line not through the origin

Answer: B

Limit of Proportionality (Load–Extension Graph)

76. The limit of proportionality is the point on a load–extension graph where

A. the object breaks

B. the straight line ends and the graph begins to curve

C. extension becomes zero

D. the load becomes zero

Answer: B

77. Beyond the limit of proportionality, the extension is

A. directly proportional to load

B. zero

C. no longer directly proportional to load

D. always smaller than before

Answer: C

78. On a load–extension graph, “proportional” means

A. load stays constant as extension increases

B. doubling load doubles extension

C. extension stays constant as load increases

D. load decreases when extension increases

Answer: B

79. A student is using Hooke’s law to calculate k. Which data should they use?

A. any part of the graph

B. only data beyond the limit of proportionality

C. only data in the straight-line region before the limit of proportionality

D. only the maximum load point

Answer: C

80. Which statement about the limit of proportionality is correct?

A. It is the point where the spring snaps

B. It is where the graph first starts to deviate from a straight line

C. It is where the extension stops increasing

D. It is always the highest load on the graph

Answer: B

81. A load–extension graph is straight up to 6 N. After that it curves. The limit of proportionality is

A. 0 N

B. 3 N

C. 6 N

D. 9 N

Answer: C

82. If the load is doubled and the extension more than doubles, the spring is

A. still in the proportional region

B. beyond the limit of proportionality

C. showing zero friction

D. showing constant velocity

Answer: B

83. On a load–extension graph, which label best marks the limit of proportionality?

A. the point where the line first becomes curved

B. the point where extension is maximum

C. the point where the line crosses the x-axis

D. the point where load is zero

Answer: A

84. A spring has a constant gradient on its force–extension graph up to a certain point. This means that up to that point

A. k is changing

B. k is constant

C. the spring has broken

D. friction is increasing

Answer: B

85. A student says, “The limit of proportionality is where the spring becomes permanently stretched.” For this syllabus point, the best correction is

A. correct, they mean elastic limit

B. incorrect, it is where the graph stops being a straight line

C. incorrect, it is where the graph becomes horizontal

D. correct, it is always the maximum load

Answer: B

86. The equation 

F

=

m

a

F=ma shows that force equals

A. mass ÷ acceleration

B. mass × acceleration

C. acceleration ÷ mass

D. mass + acceleration

Answer: B

87. The unit of force is

A. kg

B. m/s

C. N

D. N/m

Answer: C

88. A resultant force of 18 N acts on a mass of 3.0 kg. What is the acceleration?

A. 0.17 m/s²

B. 6.0 m/s²

C. 15 m/s²

D. 54 m/s²

Answer: B

89. A force of 10 N produces an acceleration of 2.5 m/s². What is the mass?

A. 0.25 kg

B. 4.0 kg

C. 12.5 kg

D. 25 kg

Answer: B

90. A 5.0 kg trolley accelerates at 1.2 m/s². What resultant force acts on it?

A. 0.24 N

B. 4.2 N

C. 6.0 N

D. 10 N

Answer: C

91. A resultant force acts to the left on an object. The object’s acceleration is

A. always to the right

B. always to the left

C. always upward

D. zero

Answer: B

92. A car is moving forward but slowing down. The resultant force on the car is

A. forward

B. backward

C. zero

D. upward

Answer: B

93. Two objects experience the same resultant force. Object X has greater mass than object Y. Compared to Y, object X will have

A. greater acceleration

B. smaller acceleration

C. the same acceleration

D. zero acceleration

Answer: B

94. If the resultant force on an object is zero, then its acceleration is

A. maximum

B. negative

C. zero

D. increasing

Answer: C

95. Which situation must have a non-zero resultant force?

A. A book resting on a table

B. A car moving at constant speed in a straight line

C. A ball changing direction while keeping the same speed

D. A trolley stationary on a level surface

Answer: C

Newton’s First Law (Inertia)

96. Newton’s First Law is best described as

A. force equals mass × acceleration

B. every action has an equal and opposite reaction

C. an object stays at rest or moves at constant velocity unless acted on by a resultant force

D. acceleration depends only on speed

Answer: C

97. Inertia is the tendency of an object to

A. speed up

B. resist changes in motion

C. fall faster

D. produce friction

Answer: B

98. Which has the greatest inertia?

A. 0.2 kg football

B. 2 kg bowling ball

C. 20 kg suitcase

D. 2000 kg car

Answer: D

Newton’s Second Law

99. Newton’s Second Law states that acceleration is

A. proportional to mass and inversely proportional to force

B. proportional to resultant force and inversely proportional to mass

C. always zero

D. independent of force

Answer: B

100. A constant resultant force acts on an object of constant mass. The acceleration will be

A. constant

B. decreasing

C. increasing

D. zero

Answer: A

101. Newton’s Third Law states that when two objects interact, they exert forces that are

A. unequal and opposite

B. equal and opposite

C. equal and in the same direction

D. unrelated

Answer: B

102. Action–reaction forces do not cancel each other out because they

A. act in the same direction

B. act on different objects

C. have different sizes

D. occur at different times

Answer: B

103. When a person walks forward, the foot pushes the ground backward. The reaction force is

A. the ground pushes the person forward

B. the ground pushes the person backward

C. the person pulls the ground forward

D. air resistance pushes the person forward

Answer: A

104. A swimmer moves forward because

A. water pulls the swimmer forward

B. swimmer pushes water forward

C. swimmer pushes water backward and water pushes swimmer forward

D. gravity pushes swimmer forward

Answer: C

105. A rocket moves upward because

A. it pushes against air

B. gases push upward on the rocket

C. gases are expelled downward and push back on the rocket

D. upthrust is always greater than weight

Answer: C

106. A gun recoils backward when a bullet is fired forward. This is because

A. friction pushes the gun back

B. the bullet exerts an equal and opposite force on the gun

C. the gun exerts a bigger force than the bullet

D. gravity pulls the gun backward

Answer: B

107. Which pair is an action–reaction pair?

A. weight of a book and reaction force from the table on the book

B. friction on a box and weight of the box

C. force of hand on wall and force of wall on hand

D. driving force on a car and air resistance on the car

Answer: C

108. A student says, “The bigger object exerts a bigger force in an interaction.” The correct idea is

A. true, bigger mass means bigger force always

B. true, because heavier objects push harder

C. false, both forces are equal in size

D. false, because only one object exerts a force

Answer: C

Thank You!

Sana Shariq

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