Q.1 Which of the following is Newton’s First Law also known as?
Law of Force
Law of Acceleration
Law of Inertia
Law of Motion
Explanation - Newton’s First Law states that a body continues in its state of rest or uniform motion unless acted upon by an external force. This is the law of inertia.
Correct answer is: Law of Inertia
Q.2 If the net force on a body is zero, its acceleration will be?
Maximum
Minimum
Zero
Infinite
Explanation - According to Newton’s Second Law, force is mass times acceleration. If net force is zero, acceleration must also be zero.
Correct answer is: Zero
Q.3 A body of mass 10 kg is acted upon by a force of 20 N. Its acceleration is?
0.5 m/s²
2 m/s²
5 m/s²
10 m/s²
Explanation - By F = ma, a = F/m = 20/10 = 2 m/s².
Correct answer is: 2 m/s²
Q.4 The unit of force in SI system is?
Dyne
Newton
Joule
Pascal
Explanation - In SI, the unit of force is Newton (N), defined as the force that produces an acceleration of 1 m/s² on a mass of 1 kg.
Correct answer is: Newton
Q.5 Friction always acts in which direction?
Same as motion
Opposite to motion
Perpendicular to surface
Along weight
Explanation - Friction opposes the relative motion between two surfaces in contact.
Correct answer is: Opposite to motion
Q.6 Which of the following is not a type of friction?
Static friction
Kinetic friction
Rolling friction
Elastic friction
Explanation - Elastic friction is not a recognized type; the main types are static, kinetic, and rolling friction.
Correct answer is: Elastic friction
Q.7 The force required to just start motion is called?
Kinetic friction
Static friction
Rolling friction
Limiting friction
Explanation - The maximum static friction before motion starts is called limiting friction.
Correct answer is: Limiting friction
Q.8 Newton’s Third Law states that for every action, there is?
Equal and opposite reaction
Double reaction
Balanced force
Frictional force
Explanation - Action and reaction forces are equal in magnitude and opposite in direction.
Correct answer is: Equal and opposite reaction
Q.9 The coefficient of friction depends on?
Nature of surfaces
Mass of body
Area of contact
Volume of body
Explanation - The coefficient of friction depends only on the roughness and material of the surfaces in contact, not on mass or area.
Correct answer is: Nature of surfaces
Q.10 If a horse pulls a cart, the cart pulls the horse with equal force. The cart still moves because?
Horse is stronger
Friction balances forces
Action and reaction act on different bodies
Cart resists less
Explanation - Action and reaction forces act on different bodies, so they do not cancel each other out.
Correct answer is: Action and reaction act on different bodies
Q.11 Which instrument is used to measure friction?
Spring balance
Barometer
Manometer
Ammeter
Explanation - A spring balance is used to measure force, including the force of friction.
Correct answer is: Spring balance
Q.12 Which friction is greater?
Static friction
Kinetic friction
Rolling friction
All are equal
Explanation - Static friction is generally greater than kinetic friction for the same surfaces.
Correct answer is: Static friction
Q.13 The direction of friction is always?
Along motion
Against relative motion
Along normal
None of these
Explanation - Friction resists the relative motion of two surfaces, acting opposite to motion.
Correct answer is: Against relative motion
Q.14 Which one of the following reduces friction?
Lubrication
Increasing roughness
Greater weight
Inclination
Explanation - Lubrication creates a thin layer between surfaces, reducing direct contact and friction.
Correct answer is: Lubrication
Q.15 The SI unit of coefficient of friction is?
Newton
Dimensionless
m/s²
kg
Explanation - Coefficient of friction is the ratio of force of friction to normal force and has no unit.
Correct answer is: Dimensionless
Q.16 The tendency of a body to resist change in its state of motion is?
Momentum
Impulse
Inertia
Force
Explanation - Inertia is the property of matter that resists changes in motion or rest.
Correct answer is: Inertia
Q.17 Force is a ______ quantity.
Scalar
Vector
Dimensionless
Unitless
Explanation - Force has both magnitude and direction, making it a vector quantity.
Correct answer is: Vector
Q.18 If a block slides on a horizontal surface, work done by friction is?
Positive
Negative
Zero
Infinite
Explanation - Friction acts opposite to displacement, so the work done by friction is negative.
Correct answer is: Negative
Q.19 When a body is moving with uniform velocity, the net force on it is?
Zero
Constant
Maximum
Variable
Explanation - Uniform velocity means no acceleration; hence net force is zero.
Correct answer is: Zero
Q.20 Which law explains the recoil of a gun?
Newton’s First Law
Newton’s Second Law
Newton’s Third Law
Law of Gravitation
Explanation - Recoil is due to equal and opposite reaction when bullet is fired forward.
Correct answer is: Newton’s Third Law
Q.21 If the force is doubled on a body of constant mass, acceleration becomes?
Half
Double
Constant
Zero
Explanation - Acceleration is directly proportional to force when mass is constant.
Correct answer is: Double
Q.22 The angle at which a body just begins to slide on an inclined plane is called?
Repose angle
Sliding angle
Angle of friction
Inclination angle
Explanation - The angle of inclination at which motion just begins is called angle of friction.
Correct answer is: Angle of friction
Q.23 Which type of friction is least?
Static
Kinetic
Rolling
All equal
Explanation - Rolling friction is much smaller compared to static and kinetic friction.
Correct answer is: Rolling
Q.24 The product of mass and acceleration gives?
Force
Momentum
Impulse
Inertia
Explanation - Newton’s Second Law: F = ma.
Correct answer is: Force
Q.25 The motion of a body on a rough surface stops due to?
Gravity
Inertia
Friction
Normal force
Explanation - Friction opposes motion and causes the body to stop on a rough surface.
Correct answer is: Friction