TNPSC Physics Laws of Motion Quiz 4 – Important MCQs with Answers

TNPSC Physics Laws of Motion Quiz 4 – Key Concepts

Mastering the Physics Laws of Motion Quiz requires a clear understanding of concepts like force, inertia, momentum, and Newton’s laws. This section explains important ideas through laws of motion MCQ with answers and simplified explanations, helping you solve TNPSC physics MCQ questions with confidence.

By practicing these Newton laws of motion MCQ and real-life examples, you can strengthen your fundamentals and improve your performance in competitive exams through this physics laws of motion quiz.

👉 These concepts will help you answer laws of motion MCQ with answers and improve your TNPSC General Science score.

Newton’s First Law (Law of Inertia)

An object remains at rest or in motion unless acted upon by an external force.

• Inertia is resistance to change
• Applies to both rest and motion

👉 Example: Passenger leans forward when bus stops suddenly

👉 Important for: Inertia-based questions

Newton’s Second Law (Force & Acceleration)

Force is equal to mass × acceleration.

• More force → more acceleration
• More mass → less acceleration

👉 Example: Light object moves faster than heavy object

👉 Important for: Force, acceleration MCQs

Newton’s Third Law (Action & Reaction)

Every action has an equal and opposite reaction.

• Forces occur in pairs
• Equal magnitude, opposite direction

👉 Example: Rocket launch, gun recoil

👉 Important for: Interaction-based questions

Momentum

Momentum is the product of mass and velocity.

• More speed → more momentum
• More mass → more momentum

👉 Example: Truck is harder to stop than bicycle

👉 Important for: Stopping, collision questions

Impulse

Impulse is force acting over a short time.

• Impulse = Force × Time
• Changes momentum

👉 Example: Bat hitting ball

👉 Important for: Impact questions

Air Resistance (Drag)

Air resistance opposes motion in air.

• More speed → more drag
• Streamlined shape reduces drag

👉 Example: Cyclists bend forward

👉 Important for: Speed-related questions

Friction

Friction opposes motion between surfaces.

• Slows down objects
• Helps in stopping

👉 Example: Rolling ball stops

👉 Important for: motion stopping questions

Real-Life Examples (Mapped to This Quiz Questions)

Inertia (Q1, Q12, Q17, Q20)

When a bus suddenly stops, passengers move forward.
👉 This happens because your body was in motion and wants to continue moving (inertia).

Another case: When a car suddenly starts → you move backward

• Seat belts stop your forward motion during sudden braking

👉 Exam Link:

• Why passengers lean forward?
• Why seat belts are used?

Impulse (Q2)

A cricket bat hits the ball for a very short time but applies a large force.
👉 This changes the momentum of the ball quickly.

Another case: Airbags increase time of impact → reduce force → save life

👉 Exam Link:

• Force acting for short time = impulse

Momentum (Q3, Q9)

A fast-moving truck is harder to stop than a bicycle.
👉 Because truck has more mass → more momentum

Another case: Running person is harder to stop than walking person

👉 Exam Link:

• Momentum increases with velocity
• Why heavy vehicles are hard to stop?

Inertia & Mass (Q4, Q18)

A heavy stone is harder to push than a small ball.
👉 Because heavier objects have more inertia

Another case: Loaded cart vs empty cart

👉 Exam Link:

• Which factor affects inertia? → Mass

Force & Acceleration (Q5, Q7)

If you throw:

• Tennis ball → goes far
• Cricket ball → goes less

👉 Same force → lighter object accelerates more

Another case: Empty trolley moves faster than loaded trolley

👉 Exam Link:

• Mass vs acceleration

Air Resistance (Q6)

Cyclists bend forward while riding fast.
👉 This reduces air resistance and increases speed

Another case: Sports cars have streamlined shapes

👉 Exam Link:

• Why bending forward increases speed?

Action–Reaction (Q8, Q14)

When you walk:
👉 You push ground backward → ground pushes you forward

Another case: Rocket moves forward by pushing gases backward

• Gun recoils backward when fired

👉 Exam Link:

• Equal and opposite forces

Friction (Q13)

A rolling ball stops after some time.
👉 Because friction opposes motion

Another case: Brakes use friction to stop vehicles

👉 Exam Link:

• What stops a moving object?

Direction Change (Q19)

When a car turns:
👉 Force is applied to change direction

Another case: Circular motion (bike turning on road)

👉 Exam Link:

• What is needed to change direction?

Vector Quantity (Q10)

Speed: 60 km/h ❌ (no direction)
Velocity: 60 km/h north ✅

👉 Only velocity includes direction

👉 Exam Link:

• Which has magnitude + direction?

Effects of Force (Q11, Q15)

Kicking a football: 👉 Changes speed and direction

Pressing a sponge: 👉 Changes shape

👉 Exam Link:

• Effects of force

Real-Life Applications of Laws of Motion

• Bus braking → inertia
• Seat belts → safety from inertia
• Rocket launch → action-reaction
• Cycling fast → air resistance
• Heavy vehicles → more momentum
• Brakes → friction

👉 These examples help in solving TNPSC Physics MCQs easily.

Final Revision Boost

✔ Heavy → more inertia
✔ Light → more acceleration
✔ Fast → more momentum
✔ Force → changes motion
✔ Friction → stops motion
✔ Action = Reaction

For more detailed explanation, refer:
🔗 NCERT Class 11 Physics – Laws of Motion