9th class Physics unit 4 MCQs
chapter 4 MCQs 9th Class Physics
Turning Effect of Forces:
1. The forces which are parallel to each other are called:
a. Unlike parallel forces
b. Parallel forces
c. Unparallel forces
d. Like parallel forces
2. Like parallel forces are parallel to each other and have ……… direction:
a. Equal
b. Same
c. Upward
d. Opposite
3. The weight of different bodies is an example of:
a. Upward forces
b. Like parallel forces
c. Downward forces
d. Unlike parallel forces
4. Unlike parallel forces are parallel to each other and have ……… direction:
a. Equal
b. Same
c. Upward
d. Opposite
5. When an apple is suspended with a string, then the weight and tension in the string are:
a. Vertical forces
b. Unlike parallel forces
c. Downward forces
d. Like parallel forces
6. When some people push the bus in the forward direction by applying forces it is an example of:
a. Forward forces
b. Unlike parallel forces
c. Backward forces
d. Like parallel forces
7. The number of forces that can be added by head to tail rule are:
a. Four
b. Two
c. Any number
d. Three
8. The number of vectors that can be added by head to tail rule is:
a. Four
b. One
c. Any number
d. Two
9. A force that has the same effect as the combined effect of all the forces to be added is called:
a. Additional force
b. Net force
c. Single force
d. Resultant force
10. In head to tail rule, the head of the resultant vector coincides with the head of ………:
a. Last vector
b. First vector
c. Both
d. None
11. In head to tail rule, the tail of the resultant vector coincides with the tail of ………:
a. Last vector
b. First vector
c. Both
d. None
12. Resultant vector is represented by:
a. F
b. R
c. S
d. V
13. Head to tail rule is a ……… method:
a. Vertical
b. Graphical
c. Plane
d. Horizontal
14. The number of perpendicular components of a force are:
a. Three
b. One
c. Four
d. Two
15. A force of 10N is making an angle of 30 with the horizontal. Its horizontal components will be:
a. 7N
b. 4N
c. 8.7N
d. 5N
16. Sinθ=?
a. perpendicular hypotenuse
b. perpendicular base
c. base perpendicular
d. base hypotenuse
17. Cosθ=?
a. base hypotenuse
b. perpendicular base
c. Perpendicular hypotenuse
d. base perpendicular
18. Tan 45°is equal to:
a. 0.577
b. 0.5
c. 1
d. 1.732
19. Sin 45 is equal to:
a. 0.707
b. 0
c. 1
d. 0.5
20. Sin 45° = Cos 45° = ………
a. 0.866
b. 1.732
c. 0.707
d. Undefined
21. The value of sin 90° is:
a. 10
b. 0
c. 0.5
d. 1
22. The number of perpendicular components of a vector are:
a. Two
b. Four
c. One
d. Three
23. Formula for the direction of resultant force with the help of rectangular components is:
a. θ=sin-1FyFx
b. θ=tan-1FyFx
c. θ=cos-1FyFx
d. θ=tan-1FxFy
24. The direction of force ‘F’ with x axis is given by:
a. θ=sin-1FyFx
b. θ=tan-1FyFx
c. θ=cos-1FyFx
d. θ=tan-1FxFy
25. Complete the equation: θ= ………:
a. θ=sin-1FyFx
b. θ=tan-1FyFx
c. θ=tan-1FyFx
d. θ=tan-1FxFy
26. In a right angled triangle, length of base is 4 cm and its\ hypotenuse if 5 cm. The length of a perpendicular is:
a. 20 cm
b. 1 cm
c. 9 cm
d. 3 cm
27. A force of 10 N makes an angle of 90 with x-axis. Its horizontal component is:
a. Zero
b. 10N
c. Maximum
d. 5N
28. In a right angled triangle, length of base is 4 cm and perpendicular is 3 cm. then its tan ?? is equal to:
a. 1
b. 0.8
c. 0.6
d. 0.75
29. If Fy = 4N and Fx = 3N, what is the magnitude of resultant force?
a. 12 N
b. 7 N
c. 10 N
d. 5 N
30. Tanθ=?
a. base perpendicular
b. perpendicular base
c. base hypotenuse
d. perpendicular hypotenuse
31. In a right angled triangle, the horizontal component is called:
a. Hypotenuse
b. Base
c. Right angle
d. Perpendicular
32. In a right angled triangle, the vertical component is called:
a. Hypotenuse
b. Base
c. Right angle
d. Perpendicular
33. The magnitude of resultant force can be found by:
a. F=Fx2+Fy2
b. F2=Fx2+Fy2
c. F=Fx2-Fy2
d. F2=Fx+Fy
34. In a right-angled triangle, the angle opposite to hypotenuse is called:
a. Right angle
b. Base
c. Straight side
d. Perpendicular
35. In a right-angled triangle, Fx =?
a. FTanθ
b. Fsinθ
c. Sinθ
d. FCosθ
36. In a right-angled triangle, Fy =?
a. FTanθ
b. FSinθ
c. Sinθ
d. FCosθ
37. The turning effect of a force is called:
a. Pressure
b. Momentum
c. Work
d. Torque
38. Torque is equal to:
a. T=F×t
b. T=Ft
c. T=F×L
d. T=FL
39. In SI, unit of torque is:
a. Nm2
b. Nm
c. Ns
d. Nm-1
40. Longer moment arm can reduce:
a. Moment of force
b. Torque
c. Rotation
d. Force
41. Longer moment arm can increase:
a. Rotation
b. Torque
c. Acceleration
d. Force
42. Shorter moment arm produce ……… torque:
a. Equal
b. Greater
c. Same
d. Less
43. Torque depends upon ……… factors:
a. Four
b. Two
c. Five
d. Three
44. When we twist a water tap, we produce:
a. Rotation
b. Force
c. Torque
d. None
45. Greater force produce ……… amount of torque:
a. Same
b. Small
c. Different
d. Greater
46. The purpose of fixing the handle of the door at the outer edge is to produce ……… torque:
a. Same
b. Small
c. Different
d. Greater
48. 1 Nm is equal to:
a. kgms-1
b. kgm2 s-2
c. kgms-2
d. kgm2 s-1
49. The torque produced in the direction of clock is called:
a. Direct torque
b. Clock wise torque
c. Indirect torque
d. Anti-clock wise torque
50. The torque produced in the opposite direction of clock is called
a. Direct torque
b. Clock wise torque
c. Indirect torque
d. Anti-clock wise torque
51. The point where the applied force causes the system to move without rotation is called:
a. Axis of Rotation
b. Center of mass
c. Center of Gravity
d. None
52. The centre of gravity of a triangle is at:
a. Centre of axis
b. Centre
c. Point of intersection of diagonals
d. Point of intersection of medians
53. The centre of gravity of uniform ……… sheet is the point of intersection of its diagonals:
a. Circular ring
b. Triangle
c. Square
d. Solid cylinder
54. Centre of gravity of a sphere is at:
a. Radius of a sphere
b. Centre of a sphere
c. Outside of a sphere
d. None of the above
55. The centre of gravity of an irregular shaped body can m be found with the help of:
a. Plumb line
b. Wedge
c. Screw gauge
d. Meter rod
56. Point of intersection of medians is the centre of gravity of a uniform:
a. Solid cylinder
b. Rod
c. Triangular sheet
d. Circular ring
57. The point where the whole weight of the body acts vertically downward is called ………:
a. Axis of Rotation
b. Center of mass
c. Center of Gravity
d. None
58. The center of gravity of a circle is:
a. Point at its tangent
b. Its center point
c. Point at any chord
d. Point at its circumference
59. Two equals but unlike parallel forces having different line of action produce:
a. Equilibrium
b. A torque
c. Neutral equilibrium
d. A couple
60. A couple is formed by:
a. two equal and oppsite forces in the same line
b. two forces perpendicular to each other
c. two equal and opposite forces not in the same line
d. two like parallel forces
61. A double arm spanner produces:
a. Force
b. Couple
c. Acceleration
d. torque
62. Equation for couple is:
a. couple = F x OA
b. couple = F x AB
c. couple = F x AOB
d. couple = F x OB
63. We can rotate a steering wheel more easily by applying ………:
a. Force
b. Torque
c. Pressure
d. Couple
64. A body is said in dynamic equilibrium if it has:
a. Uniform speed and acceleration
b. Uniform acceleration
c. Zero acceleration
d. Uniform speed
65. A body is in neutral equilibrium when its centre of gravity:
a. Keeps its height if displaced
b. Is at its highest position
c. Is situated at its base
d. Is at the lowest position
66. A body is in equilibrium when its:
a. Acceleration is uniform
b. Acceleration is zero
c. Speed and acceleration is uniform
d. Speed is uniform
67. The conditions for equilibrium are:
a. Two
b. Four
c. One
d. Three
68. According to 2nd condition of equilibrium, must be zero:
a. Rotational force
b. Angular acceleration
c. Sum of forces
d. Linear acceleration
69. States of equilibrium are:
a. Two
b. Four
c. One
d. Three
70. A pencil lying horizontally is the example of:
a. Unstable equilibrium
b. Equilibrium
c. Neutral equilibrium
d. Stable equilibrium
71. An example of neutral equilibrium is:
a. Pencil at its tip
b. Football
c. Book on a table
d. Block
72. The second condition for equilibrium is:
a. ΣT=ΣF
b. ΣF=0
c. ΣT=0
d. None
73. To satisfy first condition for equilibrium, resultant ……… should be zero:
a. Velocity
b. Torque
c. Acceleration
d. Force
74. For second condition for equilibrium, resultant ……… should be zero:
a. Pressure
b. Torque
c. Acceleration
d. Force
75. The symbol sigma Σ is ……… word:
a. British
b. Greek
c. Turkey
d. Latin
76. The symbol sigma Σ means:
a. Subtraction
b. Sum
c. Multiplication
d. Resultant
77. A book lying on a table satisfies the ……… condition for equilibrium:
a. 2nd
b. 1st
c. Both
d. None
78. If a body satisfies the first condition for equilibrium, it can ………:
a. Accelerates
b. Move
c. Break
d. Rotate
79. A body is totally in the state of equilibrium, if it satisfies ……… condition for equilibrium:
a. 2nd
b. 1st
c. Both
d. None
80. Racing cars are made stable by:
a. Lowering their center of gravity
b. Increasing their speed
c. Decreasing their width
d. Decreasing their mass
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