Try each question on your own first. Use the Show Answer button only after you have selected your option, then read the explanation and revise the related concept from your chapter notes.
Explanation: Newton's first law states that an object remains in a state of rest or uniform motion unless acted upon by an external unbalanced force. This property is inertia.
2. What is the SI unit of Force?
A. Joule
B. Watt
C. Newton
D. Pascal
Answer: C. Newton
Explanation: The SI unit of force is Newton (N), which is equivalent to 1 kg·m/s².
3. Inertia of a body depends directly on its:
A. Velocity
B. Shape
C. Mass
D. Volume
Answer: C. Mass
Explanation: Mass is a measure of inertia. A heavier object with greater mass has larger inertia, offering higher resistance to change in its state of motion.
4. Mathematical formulation of Newton's Second Law of Motion gives the formula:
A. F = m / a
B. F = m × a
C. F = m × v
D. F = m × t
Answer: B. F = m × a
Explanation: According to the second law, force is the rate of change of momentum: F = dp/dt = m(v - u)/t = ma.
5. What is the SI unit of Momentum (p = mv)?
A. kg·m/s²
B. kg·m/s
C. N·m
D. m/s²
Answer: B. kg·m/s
Explanation: Momentum = Mass × Velocity = kg × (m/s) = kg·m/s.
6. A fielder pulls his hands backwards while catching a fast-moving cricket ball to:
A. Decrease the time taken to stop the ball
B. Increase the rate of change of momentum
C. Increase time interval, thereby reducing force on hands
D. Exert higher force on the ball
Answer: C. Increase time interval, thereby reducing force on hands
Explanation: By pulling hands back, time (t) increases, which lowers the rate of change of momentum (F = Δp/t) and reduces impact force on hands.
7. According to Newton's Third Law of Motion, action and reaction forces act on:
A. The same body in the same direction
B. Different bodies in opposite directions
C. The same body in opposite directions
D. Different bodies in the same direction
Answer: B. Different bodies in opposite directions
Explanation: Action and reaction forces are always equal in magnitude and opposite in direction, acting simultaneously on two different interacting bodies.
8. Recoil velocity of a gun after firing a bullet is an application of:
A. Law of Conservation of Energy
B. Law of Conservation of Mass
C. Law of Conservation of Momentum
D. Newton's Law of Gravitation
Answer: C. Law of Conservation of Momentum
Explanation: Total momentum before firing (0) equals total momentum after firing (bullet momentum + recoil gun momentum = 0).
9. When a bus suddenly starts moving, passengers tend to fall backwards due to:
A. Inertia of motion
B. Inertia of rest
C. Inertia of direction
D. Gravitational pull
Answer: B. Inertia of rest
Explanation: The lower body in contact with the bus floor comes into motion, while the upper body resists movement due to inertia of rest, causing a backward fall.
10. Calculate the force required to produce an acceleration of 2 m/s² in an object of mass 5 kg.
This page contains a chapter-wise objective practice set. Try the questions without checking the answer first, then use the explanation to understand the point you missed. The current page contains 10 questions, so you can practise in smaller sets when you are revising.
Quick revision tip
After the practice set, write down the question numbers you missed and revise only those concepts once more. This makes MCQ practice more useful than repeatedly attempting the same questions without reviewing mistakes.
