Class 11 Physics — Chapter 7: System of Particles and Rotational Motion
66 practice questions · 22 Easy · 22 Medium · 22 Hard
Practise Class 11 Physics Chapter 7, "System of Particles and Rotational Motion", with 66 NCERT-aligned multiple-choice questions. The set is split into 22 Easy, 22 Medium and 22 Hard questions, so you can warm up on the fundamentals and then push into the exam-level problems that separate top scorers in CBSE Board exams, JEE Main, JEE Advanced and NEET UG.
"System of Particles and Rotational Motion" is one of the chapters where numerical problem-solving, derivations and conceptual application really pays off. Each MCQ on this chapter is timed and uses exam-grade marking (+2 correct, −1 wrong, 0 skipped), training the same accuracy-under-pressure that real papers demand. Every question carries a short explanation, so a wrong answer becomes a quick lesson rather than a dead end — the fastest way to close gaps before a test.
Use this chapter as targeted revision: attempt the Easy set first to confirm your basics on System of Particles and Rotational Motion, then move to Medium and Hard to test application and problem-solving. Your accuracy, streaks and XP save automatically, and the chapter feeds into your overall Class 11 Physics mastery score. A few sample questions are shown below; sign in free to practise all 66.
Key concepts: System of Particles and Rotational Motion (Class 11 Physics)
This chapter covers the centre of mass, torque and angular momentum, the moment of inertia, and the rotational analogues of the laws of motion.
- Centre of mass
- The point that moves as if all the system's mass were concentrated there and external forces acted there.
- Torque & angular momentum
- Torque τ = r×F causes rotation; angular momentum L = Iω; torque is the rate of change of L.
- Moment of inertia
- The rotational analogue of mass, I = Σmr²; depends on mass distribution and the axis.
- Rotational dynamics
- τ = Iα is the rotational form of Newton's second law; rotational KE = ½Iω².
- Conservation of angular momentum
- When net external torque is zero, L = Iω stays constant (e.g. a spinning skater pulling in arms).
Key formulas — System of Particles and Rotational Motion
💡 Exam tips for System of Particles and Rotational Motion
- Every linear quantity has a rotational analogue: m→I, F→τ, p→L, a→α.
- Conservation of angular momentum explains why pulling mass inward (smaller I) speeds up rotation.
Sample questions
Centre of mass of a uniform rod is at:
Uniform body → COM at geometric centre.
Moment of inertia of a thin ring about its central axis (mass M, radius R):
All mass at distance R: I = MR².
Moment of inertia of a solid sphere about diameter:
I = (2/5)MR² for solid sphere.
System of Particles and Rotational Motion — FAQs
What are the key concepts in Class 11 Physics System of Particles and Rotational Motion?+
This chapter covers the centre of mass, torque and angular momentum, the moment of inertia, and the rotational analogues of the laws of motion. Key ideas include Centre of mass, Torque & angular momentum, Moment of inertia, Rotational dynamics, Conservation of angular momentum.
What does Class 11 Physics Chapter 7 (System of Particles and Rotational Motion) cover on XamBaaz?+
It covers 66 NCERT-aligned MCQs on "System of Particles and Rotational Motion" — 22 Easy, 22 Medium and 22 Hard — each with a timed quiz and an instant explanation, suitable for CBSE Board exams, JEE Main, JEE Advanced and NEET UG.
Are these "System of Particles and Rotational Motion" questions free to practise?+
Yes — sign in with Google to practise "System of Particles and Rotational Motion" free. Full unlimited access is ₹999/year (limited-time launch price), with no per-chapter charges.
How should I revise "System of Particles and Rotational Motion" for the exam?+
Start with the Easy quiz to confirm your fundamentals, then attempt Medium and Hard for application-level practice. Review each explanation, retry the questions you miss, and track your accuracy on this chapter until it is consistently high.
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