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physics MCQs

9th • Chapter 04

50 Questions TextBook
1

Forces that are parallel and have the same direction are called?

A
Like parallel forces
B
Unlike parallel forces
C
Concurrent forces
D
Perpendicular forces
2

The turning effect of a force is called?

A
Momentum
B
Torque
C
Power
D
Work
3

The SI unit of torque is?

A
Newton
B
Joule
C
Watt
D
Newton-metre
4

A couple is formed by two forces that are?

A
Equal and in the same direction
B
Unequal and opposite
C
Equal and opposite
D
Unequal and in the same direction
5

For a body to be in complete equilibrium, which condition must be met?

A
ΣF = 0 only
B
Στ = 0 only
C
ΣF = 0 and Στ = 0
D
ΣF ≠ 0
6

A body at rest is said to be in?

A
Dynamic equilibrium
B
Unstable equilibrium
C
Neutral equilibrium
D
Static equilibrium
7

Where is the centre of gravity of a uniform rectangle located?

A
At one corner
B
At the centre of the longest side
C
At the point of intersection of its diagonals
D
Outside the body
8

A body moving with uniform velocity is in?

A
Static equilibrium
B
Dynamic equilibrium
C
Rotational equilibrium
D
Unstable equilibrium
9

The stability of a racing car is increased by?

A
Increasing its height
B
Lowering its centre of gravity
C
Reducing its base area
D
Making it lighter
10

What provides the necessary centripetal force for the Moon to orbit the Earth?

A
Tension
B
Friction
C
Earth's gravitational pull
D
Solar wind
11

The formula for centripetal force is?

A
F = ma
B
F = m/v²r
C
F = mv²/r
D
F = vr²/m
12

A torque that produces an anticlockwise rotation is generally considered?

A
Negative
B
Zero
C
Positive
D
Neutral
13

The perpendicular distance from the axis of rotation to the line of action of the force is called?

A
Pivot
B
Moment arm
C
Lever arm
D
Both B and C
14

If a body is in translational equilibrium, what can be said about the net force acting on it?

A
It is maximum
B
It is constant but not zero
C
It is zero
D
It is negative
15

The y-component of a force F making an angle θ with the x-axis is given by?

A
F cosθ
B
F tanθ
C
F sinθ
D
F/cosθ
16

The point where the whole weight of the body appears to act vertically downward is called?

A
Centre of mass
B
Centre of gravity
C
Pivot
D
Axis of rotation
17

In a state of stable equilibrium, the centre of gravity is at its?

A
Highest position
B
Lowest position
C
Middle position
D
Outside the body
18

A body in neutral equilibrium comes to rest in its new position without any change in its?

A
Mass
B
Weight
C
Centre of mass position
D
Velocity
19

A paratrooper descending with a uniform velocity is an example of?

A
Static equilibrium
B
Unstable equilibrium
C
Dynamic equilibrium
D
Neutral equilibrium
20

The second condition of equilibrium states that the vector sum of all torques acting on a body must be?

A
Zero
B
Positive
C
Negative
D
One
21

What happens to the torque if the moment arm is doubled while the force remains constant?

A
It is halved
B
It remains the same
C
It is doubled
D
It becomes zero
22

A tight rope walker carries a long pole to?

A
Increase his weight
B
Lower his centre of gravity
C
Increase his moment of inertia
D
Look good
23

Where is the centre of gravity of a solid sphere?

A
On its surface
B
At its centre
C
Outside the sphere
D
At the bottom
24

Which of the following is an example of neutral equilibrium?

A
A book lying on a table
B
A cone balanced on its tip
C
A ball rolling on a horizontal surface
D
A chair in its normal position
25

The x-component of a force F making an angle θ with the x-axis is given by?

A
F sinθ
B
F cosθ
C
F tanθ
D
F/sinθ
26

Forces that are parallel but have opposite directions are called?

A
Like parallel forces
B
Unlike parallel forces
C
Coplanar forces
D
Vector forces
27

The process of splitting a force into its perpendicular components is called?

A
Addition of forces
B
Resolution of a force
C
Resultant force
D
Composition of forces
28

A body is said to be in equilibrium if it has no?

A
Velocity
B
Momentum
C
Acceleration
D
Mass
29

In an unopened bottle, a small force applied at a longer moment arm produces?

A
Less torque
B
More torque
C
Zero torque
D
Negative torque
30

The centre of mass of an object coincides with its centre of gravity when?

A
The object is very large
B
g is not uniform
C
g is almost uniform
D
The object is in space
31

A cone resting on its side is an example of which type of equilibrium?

A
Stable
B
Unstable
C
Neutral
D
Dynamic
32

In a cream separator, the lighter cream particles gather at the?

A
Walls of the container
B
Bottom of the container
C
Central part of the machine
D
Top surface
33

When a body is in stable equilibrium, a slight tilt causes its centre of gravity to?

A
Be lowered
B
Remain at the same height
C
Be raised
D
Move horizontally
34

Which of the following is NOT a vector quantity?

A
Force
B
Torque
C
Moment arm
D
Velocity
35

The torque produced by a couple depends on?

A
The magnitude of one force and the couple arm
B
The magnitude of both forces only
C
The direction of the forces only
D
The point of application
36

The number of perpendicular components a force can be resolved into is usually?

A
One
B
Two
C
Three
D
Four
37

The first condition of equilibrium deals with?

A
Rotational motion
B
Translational motion
C
Circular motion
D
Vibratory motion
38

A door is easier to open by applying force at the?

A
Hinge
B
Middle of the door
C
Handle (farthest from hinge)
D
Top edge
39

Which law of motion is analogous to the principle of a rotating object continuing its motion?

A
Newton's First Law
B
Newton's Second Law
C
Newton's Third Law
D
Law of Gravitation
40

When a car turns, the force that provides the necessary centripetal force is?

A
Engine thrust
B
Gravity
C
Air resistance
D
Friction between tires and road
41

What is the centre of gravity of a uniform metre rule?

A
At the 0 cm mark
B
At its centre (50 cm mark)
C
At the 100 cm mark
D
Depends on its weight
42

If the line of action of a force passes through the axis of rotation, the torque produced is?

A
Maximum
B
Minimum
C
Zero
D
Infinite
43

A body that does not deform under the action of a force is called a?

A
Soft body
B
Plastic body
C
Elastic body
D
Rigid body
44

The direction of velocity in a circular motion is always?

A
Towards the centre
B
Away from the centre
C
Along the tangent to the circle
D
Perpendicular to the tangent
45

A body in unstable equilibrium will do what after a slight tilt?

A
Return to its original position
B
Move to a new stable position
C
Continue to move further away from its original position
D
Oscillate
46

Where can the centre of gravity of a bowl lie?

A
Inside the material
B
On the rim
C
Outside the material
D
Always at the bottom
47

The sum of clockwise moments equals the sum of anticlockwise moments is known as?

A
Principle of torque
B
Principle of moments
C
First condition of equilibrium
D
Second law of motion
48

A washing machine's dryer uses which principle to dry clothes quickly?

A
Gravity
B
Friction
C
Centripetal force
D
Equilibrium
49

The two conditions of equilibrium ensure a body has neither translational nor ______ acceleration.

A
Linear
B
Rotational
C
Uniform
D
Variable
50

To turn a steering wheel, one applies a?

A
Single force
B
Couple
C
Torque
D
Both B and C