Force

The Most Comprehensive Question Bank for ICSE Class 10 Students

Multiple Choice Questions (MCQs)

Question 1
What is the unit for measuring the moment of force in the SI system?
a) Newton (N)
b) Joule (J)
c) Newton-meter (Nm)
d) Meter (m)

Solution:
c) Newton-meter (Nm)
Explanation:
The moment of force, also known as torque, is measured in Newton-meters (Nm) in the SI system.

Question 2
Which of the following conditions must be satisfied for an object to be in translational equilibrium?
a) Net force must be zero
b) Net torque must be zero
c) Both net force and net torque must be zero
d) The object must be at rest

Solution:
a) Net force must be zero
Explanation:
For translational equilibrium, the net external force acting on an object must be zero.

Question 3
What is the effect of increasing the distance from the pivot point on the moment of force?
a) Moment of force decreases
b) Moment of force remains the same
c) Moment of force increases
d) Moment of force becomes zero

Solution:
c) Moment of force increases
Explanation:
The moment of a force increases as the perpendicular distance from the pivot point to the line of action of the force increases.

Question 4
Which of the following scenarios exemplifies the use of a moment of force?
a) Pushing a car
b) Turning a screw with a screwdriver
c) Lifting a bucket of water
d) Walking on a flat surface

Solution:
b) Turning a screw with a screwdriver
Explanation:
Turning a screw with a screwdriver involves applying a force at a distance from a pivot point, creating a moment of force.

Question 5
The center of gravity of a uniform circular disc is located at:
a) The edge of the disc
b) The center of the disc
c) Any point on the disc
d) Outside the disc

Solution:
b) The center of the disc
Explanation:
For a uniform circular disc, the center of gravity is at its geometric center.

Question 6
In the context of rotational motion, when is an object said to be in rotational equilibrium?
a) When it is not rotating
b) When its rotational speed is constant
c) When the net torque acting on it is zero
d) When it rotates in a circular path

Solution:
c) When the net torque acting on it is zero
Explanation:
An object is in rotational equilibrium when the net external torque acting on it is zero.

Question 7
What does the principle of moments state for a body in equilibrium?
a) Sum of clockwise moments equals the sum of anticlockwise moments
b) Clockwise moments are always greater than anticlockwise moments
c) Anticlockwise moments are always greater than clockwise moments
d) Moments have no effect on equilibrium

Solution:
a) Sum of clockwise moments equals the sum of anticlockwise moments
Explanation:
The principle of moments states that for a body to be in equilibrium, the sum of clockwise moments about any point must equal the sum of anticlockwise moments about the same point.

Question 8
Which statement best describes the center of gravity?
a) It is always at the geometric center of an object
b) It is the point where the total weight of the object acts
c) It is fixed for all objects
d) It depends on the shape of the object

Solution:
b) It is the point where the total weight of the object acts
Explanation:
The center of gravity is the point where the total gravitational force on an object can be considered to act.

Question 9
What happens to the center of gravity of an object if its shape is changed without altering its mass?
a) It remains constant
b) It may change
c) It always moves to the object’s new geometric center
d) It shifts outside the object

Solution:
b) It may change
Explanation:
The center of gravity may change if the shape of an object is altered, as it depends on the distribution of mass.

Question 10
In the context of rotational motion, what is torque also known as?
a) Centripetal force
b) Moment of inertia
c) Moment of force
d) Angular momentum

Solution:
c) Moment of force
Explanation:
Torque is also referred to as the moment of force, representing the rotational effect produced by a force.

Question 11
What is the primary condition for rotational equilibrium?
a) The net force should be zero
b) The net torque should be zero
c) The object should be at rest
d) The angular velocity should be constant

Solution:
b) The net torque should be zero
Explanation:
For rotational equilibrium, the net external torque acting on an object must be zero.

Question 12
How does the length of a lever arm affect the effort required to lift a weight?
a) A longer lever arm requires more effort
b) A longer lever arm requires less effort
c) The lever arm length has no effect on the effort required
d) The effort is inversely proportional to the square of the lever arm length

Solution:
b) A longer lever arm requires less effort
Explanation:
A longer lever arm increases the moment of force, thereby reducing the effort required to lift a weight.

Question 13
Why do doors typically have handles far from the hinges?
a) To increase the moment of force for easier opening
b) To decrease the moment of force for easier opening
c) For aesthetic purposes
d) To reduce wear and tear on the hinges

Solution:
a) To increase the moment of force for easier opening
Explanation:
Placing handles far from the hinges increases the lever arm length, enhancing the moment of force and making it easier to open the door.

Question 14
What does the principle of moments imply for a beam in equilibrium supported at its center?
a) The beam’s weight is evenly distributed
b) The clockwise moments equal the anticlockwise moments
c) The net force on the beam is zero
d) The beam has equal lengths on either side of the support

Solution:
b) The clockwise moments equal the anticlockwise moments
Explanation:
For a beam in equilibrium, the principle of moments states that the sum of clockwise moments around the support point equals the sum of anticlockwise moments.

Question 15
What is the effect of a force applied at the center of gravity of an object?
a) It causes rotational motion
b) It causes translational motion
c) It has no effect
d) It always causes the object to topple

Solution:
b) It causes translational motion
Explanation:
Applying a force at an object’s center of gravity causes translational motion without rotation.

Question 16
How is the stability of an object affected by its center of gravity?
a) A higher center of gravity increases stability
b) A lower center of gravity increases stability
c) The center of gravity has no effect on stability
d) Stability is determined only by the object’s weight

Solution:
b) A lower center of gravity increases stability
Explanation:
An object with a lower center of gravity tends to be more stable, as it lowers the object’s overall center of mass, reducing the likelihood of toppling.

Question 17
What defines the magnitude of torque applied to a body?
a) The force applied and the angle of application
b) The force applied and the distance from the pivot
c) Only the force applied
d) Only the distance from the pivot

Solution:
b) The force applied and the distance from the pivot
Explanation:
The magnitude of torque depends on the force applied and the perpendicular distance from the line of action of the force to the pivot.

Question 18
A force acting on a door causes maximum torque when applied at:
a) The middle of the door
b) The edge of the door, perpendicular to its surface
c) The edge of the door, parallel to its surface
d) The hinge of the door

Solution:
b) The edge of the door, perpendicular to its surface
Explanation:
Maximum torque is achieved when the force is applied at the farthest point from the pivot (hinge) and perpendicular to the door’s surface.

Question 19
Which of the following correctly defines the center of gravity?
a) The point at which the weight of the body acts regardless of its position
b) The highest point of an object
c) The point where the body is supported
d) The center of the material composition of the body

Solution:
a) The point at which the weight of the body acts regardless of its position
Explanation:
The center of gravity is the point where the entire weight of a body is considered to be concentrated.

Question 20
What is the effect of a couple on a body?
a) It causes only translational motion
b) It causes only rotational motion
c) It causes both translational and rotational motion
d) It has no effect on the body

Solution:
b) It causes only rotational motion
Explanation:
A couple consists of two equal and opposite forces whose lines of action do not coincide, causing rotational motion without translation.

Question 21
When does a body experience rotational motion?
a) When forces act along the same line
b) When a couple acts on the body
c) When a single force acts through the center of gravity
d) When the net force on the body is zero

Solution:
b) When a couple acts on the body
Explanation:
A couple, which consists of two equal and opposite forces not along the same line, causes a body to experience rotational motion.

Question 22
In a seesaw, if a child sitting on one end is unable to lift the other end, what adjustment can be made to achieve balance?
a) Move the child closer to the pivot
b) Move the child further from the pivot
c) Increase the weight of the child
d) Decrease the weight of the child

Solution:
a) Move the child closer to the pivot
Explanation:
Moving the child closer to the pivot reduces the moment arm and can help achieve balance if the other side is heavier.

Question 23
What is the principle behind using a longer handle on tools like wrenches?
a) To reduce the effort needed to apply a large force
b) To increase the speed of the applied force
c) To decrease the distance over which the force acts
d) To make the tool easier to handle

Solution:
a) To reduce the effort needed to apply a large force
Explanation:
A longer handle on a wrench increases the distance from the pivot, thereby increasing torque and reducing the effort needed.

Question 24
Which condition is necessary for a body to be in static equilibrium?
a) The net force acting on the body must be moving
b) The body must be moving with a uniform velocity
c) The net force and net torque on the body must be zero
d) The body must be accelerating

Solution:
c) The net force and net torque on the body must be zero
Explanation:
For a body to be in static equilibrium, both the net force and the net torque acting on it must be zero.

Question 25
Where is the center of gravity located in a uniform rod?
a) At one of the ends
b) In the middle of the rod
c) Near the heavier side, if the rod is not uniform
d) Outside the rod

Solution:
b) In the middle of the rod
Explanation:
In a uniform rod, the center of gravity is located at its midpoint due to the symmetrical distribution of mass.

Question 26
Which factor does not affect the center of gravity of an object?
a) The shape of the object
b) The mass of the object
c) The color of the object
d) The distribution of mass in the object

Solution:
c) The color of the object
Explanation:
The center of gravity of an object is influenced by its shape and mass distribution but not by its color.

Question 27
What is the primary effect of a force acting on a body at its center of gravity?
a) It causes the body to rotate
b) It causes the body to accelerate
c) It causes the body to remain stationary
d) It causes the body to vibrate

Solution:
b) It causes the body to accelerate
Explanation:
A force acting on a body at its center of gravity causes the body to translate or accelerate without rotating.

Question 28
What determines the direction of rotation in a turning force?
a) The direction of the force applied
b) The position of the pivot point
c) The distance from the pivot point to where the force is applied
d) Both the direction of the force and the position of the pivot point

Solution:
d) Both the direction of the force and the position of the pivot point
Explanation:
The direction of rotation is determined by both the direction in which the force is applied and the position of the pivot point relative to the force.

Question 29
Which of the following is a real-life example of the principle of moments?
a) A car moving on a straight road
b) Using a seesaw in a playground
c) A ball dropping to the ground
d) Boiling water in a kettle

Solution:
b) Using a seesaw in a playground
Explanation:
A seesaw is a practical example of the principle of moments, where forces at different distances from the pivot cause rotational motion.

Question 30
What happens to the stability of an object if its base is widened, without changing its center of gravity?
a) Stability increases
b) Stability decreases
c) Stability remains unchanged
d) The object becomes neutrally stable

Solution:
a) Stability increases
Explanation:
Widening the base of an object increases its stability as it lowers the center of gravity and increases the area over which it is distributed.

Question 31
In the context of rotational motion, what does a clockwise moment indicate?
a) The rotation is in the clockwise direction
b) The rotation is in the anticlockwise direction
c) There is no rotational motion
d) The direction of rotation cannot be determined

Solution:
a) The rotation is in the clockwise direction
Explanation:
A clockwise moment implies that the rotation caused by the force or forces is in the clockwise direction.

Question 32
Why is it easier to lift a heavy object using a lever?
a) Because the lever reduces the weight of the object
b) Because the lever increases the gravitational force
c) Because the lever increases the distance over which the force is applied
d) Because the lever changes the direction of the applied force

Solution:
c) Because the lever increases the distance over which the force is applied
Explanation:
A lever makes it easier to lift a heavy object because it increases the distance from the pivot, thus requiring less force to produce the necessary torque.

Question 33
Which of the following best describes the condition for a body to be in rotational equilibrium?
a) The net external force acting on the body must be zero
b) The net external torque acting on the body must be zero
c) The body must have a uniform circular motion
d) The body must not be rotating at all

Solution:
b) The net external torque acting on the body must be zero
Explanation:
For rotational equilibrium, the net external torque (or moment of force) acting on the body must be zero.

Question 34
What effect does the application of a couple have on a body?
a) Causes only translational motion
b) Causes only rotational motion
c) Causes no motion
d) Causes both translational and rotational motion

Solution:
b) Causes only rotational motion
Explanation:
A couple consists of two equal and opposite forces that are not aligned, which causes rotational motion without translation.

Question 35
Where is the center of gravity in a uniform spherical ball?
a) At the surface of the ball
b) At any point inside the ball
c) At the center of the ball
d) Outside the ball

Solution:
c) At the center of the ball
Explanation:
In a uniform spherical ball, the center of gravity is at its geometric center due to the symmetrical distribution of mass.

Question 36
Why are door handles generally placed far from the hinges?
a) To minimize the effect of the force applied
b) To maximize the effect of the force applied
c) For aesthetic reasons
d) To protect the hinges from wear and tear

Solution:
b) To maximize the effect of the force applied
Explanation:
Placing the door handles far from the hinges maximizes the torque (moment of force) for the same applied force, making it easier to open or close the door.

Question 37
What is the significance of the center of gravity in terms of an object’s stability?
a) A higher center of gravity makes an object more stable
b) A lower center of gravity makes an object more stable
c) The center of gravity has no impact on stability
d) Stability depends only on the object’s weight, not its center of gravity

Solution:
b) A lower center of gravity makes an object more stable
Explanation:
An object is more stable if it has a lower center of gravity, as this lowers the overall center of mass and reduces the likelihood of tipping over.

Question 38
In a simple lever system, how can you increase the mechanical advantage?
a) By decreasing the length of the lever arm
b) By increasing the length of the lever arm
c) By applying the force closer to the fulcrum
d) By reducing the weight to be lifted

Solution:
b) By increasing the length of the lever arm
Explanation:
Increasing the length of the lever arm increases the mechanical advantage, allowing a smaller force to move a larger load.

Question 39
What does a zero net torque on a body imply about its state of motion?
a) The body is accelerating
b) The body is moving with a constant velocity
c) The body is not rotating
d) The body is in rotational equilibrium

Solution:
d) The body is in rotational equilibrium
Explanation:
A zero net torque on a body implies that it is in rotational equilibrium, which means it is either not rotating or rotating at a constant angular velocity.

Question 40
If you want to open a nut with a wrench and find it difficult, what should you do to make it easier?
a) Use a wrench with a shorter handle
b) Use a wrench with a longer handle
c) Apply the force closer to the pivot point
d) Apply the force in the opposite direction

Solution:
b) Use a wrench with a longer handle
Explanation:
Using a wrench with a longer handle increases the torque for the same amount of force applied, making it easier to open the nut.

Question 41
What is the main factor that determines the stability of an object?
a) The height of the object
b) The weight of the object
c) The position of the center of gravity relative to the base of support
d) The material of the object

Solution:
c) The position of the center of gravity relative to the base of support
Explanation:
Stability is primarily determined by the position of the center of gravity in relation to the base of support. A lower center of gravity and a wider base of support generally increase stability.

Question 42
In the context of rotational motion, what is the significance of the ‘moment arm’?
a) It is the distance from the axis of rotation to the point where force is applied
b) It is the length of the object being rotated
c) It is the amount of force applied to create rotation
d) It is the speed at which the object rotates

Solution:
a) It is the distance from the axis of rotation to the point where force is applied
Explanation:
The moment arm is the perpendicular distance from the axis of rotation to the line of action of the force, and it determines the effectiveness of the force in causing rotational motion.

Question 43
What condition must be met for an object to be in both translational and rotational equilibrium?
a) The net force must be zero, and the net torque must be zero
b) The net force must be constant, and the net torque must be zero
c) The net force and net torque must be equal
d) The net force must be zero, regardless of the torque

Solution:
a) The net force must be zero, and the net torque must be zero
Explanation:
For an object to be in both translational and rotational equilibrium, the net external force acting on it must be zero, and the net external torque must also be zero.

Question 44
Which of the following increases the mechanical advantage in a lever system?
a) Decreasing the distance between the effort and the fulcrum
b) Increasing the distance between the load and the fulcrum
c) Increasing the distance between the effort and the fulcrum
d) Decreasing the distance between the load and the effort

Solution:
c) Increasing the distance between the effort and the fulcrum
Explanation:
Increasing the distance between the effort (applied force) and the fulcrum increases the mechanical advantage, allowing a smaller force to move a larger load.

Question 45
Why are bicycle pedals designed to be a certain distance from the center of the bicycle?
a) To increase speed
b) To reduce effort
c) To increase the torque
d) To make the bicycle more compact

Solution:
c) To increase the torque
Explanation:
The distance of the pedals from the center of the bicycle increases the moment arm, thereby increasing the torque for the same force applied, making pedaling more effective.

Question 46
What is the effect of applying a force at a point above the center of gravity of a standing object?
a) The object will move upwards
b) The object will move downwards
c) The object may topple
d) The object will remain stationary

Solution:
c) The object may topple
Explanation:
Applying a force above an object’s center of gravity can create a torque that may cause the object to topple, especially if the line of action of the force falls outside the base of support.

Question 47
What is the primary use of the concept of center of gravity in engineering and design?
a) To determine the color scheme of a structure
b) To ensure structural stability and balance
c) To calculate the cost of materials
d) To enhance the aesthetic appeal of structures

Solution:
b) To ensure structural stability and balance
Explanation:
In engineering and design, the concept of the center of gravity is crucial for ensuring the structural stability and balance of objects and structures.

Question 48
How does a fulcrum work in a lever system?
a) It multiplies the applied force
b) It changes the direction of the applied force
c) It serves as the pivot point around which the lever rotates
d) It reduces the weight of the object being lifted

Solution:
c) It serves as the pivot point around which the lever rotates
Explanation:
In a lever system, the fulcrum is the pivot point around which the lever rotates. It doesn’t multiply the force but allows the lever to amplify force or distance, depending on its position.

Question 49
What does the moment of inertia depend on in rotational motion?
a) The mass of the rotating object
b) The velocity of the rotating object
c) The shape and mass distribution of the object
d) The temperature of the environment

Solution:
c) The shape and mass distribution of the object
Explanation:
The moment of inertia in rotational motion depends on both the mass of the object and how that mass is distributed relative to the axis of rotation.

Question 50
Why are steering wheels in vehicles generally large in diameter?
a) To increase the turning torque
b) To make them easier to grip
c) To improve the aesthetic appearance of the vehicle
d) To reduce the speed of the vehicle

Solution:
a) To increase the turning torque
Explanation:
A larger diameter steering wheel increases the moment arm, thereby increasing the turning torque for the same amount of force, making steering easier.

Question 51
In which situation is an object said to have a stable equilibrium?
a) When displaced, it returns to its original position
b) When displaced, it moves to a new position
c) When displaced, it remains in its new position
d) When displaced, it falls over

Solution:
a) When displaced, it returns to its original position
Explanation:
An object is in stable equilibrium if, when slightly displaced, it tends to return to its original position.

Question 52
What is the significance of a low center of gravity in racing cars?
a) It increases the speed of the car
b) It enhances the fuel efficiency
c) It improves the stability and reduces the risk of toppling
d) It increases the braking distance

Solution:
c) It improves the stability and reduces the risk of toppling
Explanation:
A low center of gravity in racing cars improves stability, especially during fast turns, and reduces the risk of the car toppling over.

Question 53
What is the primary reason for using gears in machinery?
a) To change the direction of motion
b) To increase the output speed
c) To transmit rotational motion with a desired torque
d) To reduce the weight of the machinery

Solution:
c) To transmit rotational motion with a desired torque
Explanation:
Gears are used in machinery to transmit rotational motion from one part to another with the ability to modify the output torque and speed.

Question 54
When is a body said to be in unstable equilibrium?
a) When it remains stationary after being displaced
b) When it returns to its original position after being displaced
c) When it moves to a new position after being displaced
d) When it topples over after being displaced

Solution:
d) When it topples over after being displaced
Explanation:
A body is in unstable equilibrium if it topples over or moves to a new position when slightly displaced from its original position.

Question 55
Why are handles on shopping carts placed at a certain height?
a) To match the average height of users
b) To provide better control and maneuverability
c) To reduce the manufacturing cost
d) To increase the storage capacity of the cart

Solution:
b) To provide better control and maneuverability
Explanation:
The placement of handles on shopping carts is designed to provide users with better control and maneuverability, allowing for efficient application of force and torque.

Question 56
What effect does widening the base of a tower crane have on its stability?
a) Decreases stability
b) Increases stability
c) Has no effect on stability
d) Makes the crane more prone to toppling

Solution:
b) Increases stability
Explanation:
Widening the base of a tower crane increases its stability by providing a larger area of support and lowering the center of gravity, reducing the likelihood of toppling.