Friction MCQ Quiz - Objective Question with Answer for Friction - Download Free PDF

The Correct answer is Both Assertion and Reason are correct, and Reason is the correct explanation for Assertion.

Key Points

• Friction is a force that always acts in the opposite direction to the motion of an object, resisting its movement.
• This opposition is due to the interaction of the surfaces in contact, specifically their irregularities.
• The Reason correctly explains the Assertion, as friction is caused by the interlocking of microscopic irregularities on the surfaces of objects in contact.
• When two surfaces come into contact, the microscopic irregularities on these surfaces interlock, creating resistance to motion.
• Friction is a crucial force in everyday life as it enables activities like walking, driving, and holding objects.
• The explanation of friction aligns with the principles of physics, supporting the Assertion with accurate reasoning.
• This concept is widely applied in designing machines, vehicles, and surfaces to either minimize or utilize friction.

Additional Information

• Friction is a force that opposes the relative motion or tendency of such motion of two surfaces in contact.
• There are several types of friction: static, sliding (kinetic), rolling, and fluid friction.
• The coefficient of static friction is usually higher than the coefficient of sliding friction for the same materials.
• Understanding the differences between static and sliding friction is crucial in fields like engineering and physics, where the control of friction is necessary for the design of various mechanical systems.

CONCEPT:

Non-Contact and Contact Forces

• Non-contact forces: These are forces that act on an object without any physical contact. Examples include gravitational force, magnetic force, and electrostatic force.
• Contact forces: These are forces that require physical contact between objects to act. An example is frictional force.

EXPLANATION

• Gravitational force - This is a non-contact force as it acts at a distance without physical contact.

• Friction force - This is a contact force because it requires physical contact between surfaces to act.
• Magnetic force - This is a non-contact force as it can act at a distance.
• Electrostatic force - This is a non-contact force as it can act without physical contact.

From the above analysis, friction force is the only contact force among the options.

Therefore, the correct answer is Friction force.

The correct answer is Friction.

Key Points

• Friction is the force that resists the relative motion between two surfaces in contact.
• It prevents cars from skidding by creating traction between the tyres and the road.
• Tyres are specifically designed with tread patterns to maximize friction and enhance grip on different road surfaces.
• Friction plays a critical role in braking systems, ensuring controlled deceleration and preventing accidents.
• Road conditions such as wet or icy surfaces can reduce friction, increasing the risk of skidding.

Additional Information

• Friction Force: It is a contact force that opposes relative motion between two surfaces. It acts parallel to the surface.
• Types of Friction:
  • Static Friction: Prevents motion until a threshold force is applied.
  • Kinetic Friction: Acts when objects are sliding over each other.
  • Rolling Friction: Occurs when an object rolls over a surface, as seen in tyres.
• Factors Affecting Friction: Surface roughness, material properties, and normal force between the surfaces influence the level of friction.
• Applications in Vehicle Safety: Anti-lock braking systems (ABS) and tyre tread designs are engineered to optimize friction for better control and safety.
• Negative Effects: Excessive friction can lead to wear and tear of tyres and reduced fuel efficiency due to increased resistance.

The correct answer is Both Assertion (A) and Reason (R) are the true and Reason (R) is a correct explanation of Assertion (A).Key Points

• Assertion (A) is true because a rough surface provides more contact points between the object and the surface, increasing the frictional force and reducing slipping.
• Reason (R) is also true because frictional force increases with roughness as the irregularities in the surface create more resistance.
• Both Assertion (A) and Reason (R) are related and true, and Reason (R) provides a correct explanation for Assertion (A).

Additional Information

• Frictional force:-
  • It is a force that opposes motion between two surfaces in contact.
  • It is dependent on the nature of the surfaces in contact, the normal force, and the coefficient of friction.

Key Points

• Kinetic friction occurs when two objects are moving relative to each other and rub together.
• Kinetic friction is generally less than static friction for the same materials.
• It acts opposite to the direction of motion and tries to stop the moving object.
• It is dependent on the nature of the surfaces in contact and the normal force pressing them together.

Additional Information

• Limiting friction
  • It is the maximum static friction that occurs just before an object starts moving.
  • It represents the maximum force that can be applied without causing motion.
• Rolling friction
  • It occurs when an object rolls over a surface.
  • Rolling friction is much smaller than sliding (kinetic) friction because there is less surface area in contact.
• Static friction
  • This is the friction that acts on objects that are not moving.
  • It must be overcome to start the motion of an object.
  • Static friction is generally higher than kinetic friction.

The correct answer is Both Assertion (A) and Reason (R) are the true and Reason (R) is a correct explanation of Assertion (A).Key Points

• Assertion (A) is true because a rough surface provides more contact points between the object and the surface, increasing the frictional force and reducing slipping.
• Reason (R) is also true because frictional force increases with roughness as the irregularities in the surface create more resistance.
• Both Assertion (A) and Reason (R) are related and true, and Reason (R) provides a correct explanation for Assertion (A).

Additional Information

• Frictional force:-
  • It is a force that opposes motion between two surfaces in contact.
  • It is dependent on the nature of the surfaces in contact, the normal force, and the coefficient of friction.

The correct answer is Both Assertion (A) and Reason (R) are the true and Reason (R) is a correct explanation of Assertion (A).Key Points

• Assertion (A) is true because a rough surface provides more contact points between the object and the surface, increasing the frictional force and reducing slipping.
• Reason (R) is also true because frictional force increases with roughness as the irregularities in the surface create more resistance.
• Both Assertion (A) and Reason (R) are related and true, and Reason (R) provides a correct explanation for Assertion (A).

Additional Information

• Frictional force:-
  • It is a force that opposes motion between two surfaces in contact.
  • It is dependent on the nature of the surfaces in contact, the normal force, and the coefficient of friction.

CONCEPT:

Non-Contact and Contact Forces

• Non-contact forces: These are forces that act on an object without any physical contact. Examples include gravitational force, magnetic force, and electrostatic force.
• Contact forces: These are forces that require physical contact between objects to act. An example is frictional force.

EXPLANATION

• Gravitational force - This is a non-contact force as it acts at a distance without physical contact.

• Friction force - This is a contact force because it requires physical contact between surfaces to act.
• Magnetic force - This is a non-contact force as it can act at a distance.
• Electrostatic force - This is a non-contact force as it can act without physical contact.

From the above analysis, friction force is the only contact force among the options.

Therefore, the correct answer is Friction force.

The correct answer is Friction.

Key Points

• Friction is the force that resists the relative motion between two surfaces in contact.
• It prevents cars from skidding by creating traction between the tyres and the road.
• Tyres are specifically designed with tread patterns to maximize friction and enhance grip on different road surfaces.
• Friction plays a critical role in braking systems, ensuring controlled deceleration and preventing accidents.
• Road conditions such as wet or icy surfaces can reduce friction, increasing the risk of skidding.

Additional Information

• Friction Force: It is a contact force that opposes relative motion between two surfaces. It acts parallel to the surface.
• Types of Friction:
  • Static Friction: Prevents motion until a threshold force is applied.
  • Kinetic Friction: Acts when objects are sliding over each other.
  • Rolling Friction: Occurs when an object rolls over a surface, as seen in tyres.
• Factors Affecting Friction: Surface roughness, material properties, and normal force between the surfaces influence the level of friction.
• Applications in Vehicle Safety: Anti-lock braking systems (ABS) and tyre tread designs are engineered to optimize friction for better control and safety.
• Negative Effects: Excessive friction can lead to wear and tear of tyres and reduced fuel efficiency due to increased resistance.

The Correct answer is Both Assertion and Reason are correct, and Reason is the correct explanation for Assertion.

Key Points

• Friction is a force that always acts in the opposite direction to the motion of an object, resisting its movement.
• This opposition is due to the interaction of the surfaces in contact, specifically their irregularities.
• The Reason correctly explains the Assertion, as friction is caused by the interlocking of microscopic irregularities on the surfaces of objects in contact.
• When two surfaces come into contact, the microscopic irregularities on these surfaces interlock, creating resistance to motion.
• Friction is a crucial force in everyday life as it enables activities like walking, driving, and holding objects.
• The explanation of friction aligns with the principles of physics, supporting the Assertion with accurate reasoning.
• This concept is widely applied in designing machines, vehicles, and surfaces to either minimize or utilize friction.

Additional Information

• Friction is a force that opposes the relative motion or tendency of such motion of two surfaces in contact.
• There are several types of friction: static, sliding (kinetic), rolling, and fluid friction.
• The coefficient of static friction is usually higher than the coefficient of sliding friction for the same materials.
• Understanding the differences between static and sliding friction is crucial in fields like engineering and physics, where the control of friction is necessary for the design of various mechanical systems.

Key Points

• Kinetic friction occurs when two objects are moving relative to each other and rub together.
• Kinetic friction is generally less than static friction for the same materials.
• It acts opposite to the direction of motion and tries to stop the moving object.
• It is dependent on the nature of the surfaces in contact and the normal force pressing them together.

Additional Information

• Limiting friction
  • It is the maximum static friction that occurs just before an object starts moving.
  • It represents the maximum force that can be applied without causing motion.
• Rolling friction
  • It occurs when an object rolls over a surface.
  • Rolling friction is much smaller than sliding (kinetic) friction because there is less surface area in contact.
• Static friction
  • This is the friction that acts on objects that are not moving.
  • It must be overcome to start the motion of an object.
  • Static friction is generally higher than kinetic friction.

The correct answer is opposes.

Key Points

• Friction is a force that resists the relative motion or tendency of such motion of two surfaces in contact.
• Friction acts in the opposite direction of the relative motion between two surfaces.
• It is a force that opposes the sliding or rolling of one object over another.
• Frictional forces convert kinetic energy into thermal energy.

Important Points

• Friction is essential for many everyday activities, such as walking or driving, where it provides the necessary grip.
• There are different types of friction: static, kinetic, rolling, and fluid friction.
• Reducing friction in machines can increase efficiency by decreasing the amount of energy lost as heat.
• Friction can also cause wear and tear on objects in contact over time.