Previous IIT / JEE Objective Questions
Work, Energy & Power – PAGE 4
This page contains very tough objective and integer-type questions similar to IIT-JEE Advanced. Most questions require method selection, not calculation.
Q36. (IIT-JEE Advanced)
A block slides down a smooth incline of height h and then moves on a rough horizontal surface (coefficient of friction μ). What distance does it travel on the rough surface before stopping?
Answer: h / μ
Solution Method:
Energy conserved on incline, lost only on rough surface.
mgh = μmg·s → s = h / μ
Trap: Including friction on incline incorrectly.
Q37. (IIT-JEE Advanced)
A particle moves under a conservative force. Which statement is always true?
Answer: Mechanical energy depends only on position
Why:
Work done is path-independent.
Q38. (JEE Main)
A particle of mass m has total energy E and moves in a potential field U(x). At a point where E < U(x), the particle:
Answer: Cannot exist
Reason:
KE = E − U(x) < 0 is impossible.
Q39. (IIT-JEE Advanced – Integer)
A block of mass 2 kg slides on a rough horizontal surface with coefficient of friction 0.2. Initial speed is 10 m/s. Find the stopping distance (g = 10 m/s²).
Answer: 25 m
Method:
½mv² = μmg·s → s = v² / (2μg)
s = 100 / (2 × 0.2 × 10) = 25 m
Q40. (IIT-JEE Advanced)
A particle moves in a vertical circle. At which point is the tension minimum?
Answer: At the top
Explanation:
Centripetal requirement is shared with gravity.
Q41. (JEE Main)
Power delivered by gravity to a freely falling body just before hitting ground is:
Answer: Maximum
Reason:
P = F·v, velocity is maximum at that instant.
Q42. (IIT-JEE Advanced)
A body moves such that its kinetic energy remains constant. Which force configuration is possible?
Answer: Force always perpendicular to velocity
Example:
Uniform circular motion.
Q43. (IIT-JEE Advanced – Integer)
A spring of constant 400 N/m is compressed by 10 cm. Find the energy stored.
Answer: 2 J
Calculation:
U = ½kx² = ½ × 400 × (0.1)² = 2 J
Q44. (JEE Main)
Which graph correctly represents variation of KE with speed?
Answer: Parabolic curve (KE ∝ v²)
Q45. (IIT-JEE Advanced)
A particle is released from rest in a potential field. At equilibrium position, which condition is satisfied?
Answer: dU/dx = 0
Additional:
Stable if d²U/dx² > 0
End of PAGE 4
PAGE 4 focuses on inequalities, equilibrium, and mixed objective–integer logic — exactly how IIT Advanced sets traps.
Work, Energy & Power – Complete Physics Library
This is the MASTER LIBRARY PAGE for the complete chapter Work, Energy and Power, prepared for Intermediate, IIT-JEE (Main & Advanced), NEET and competitive exams.
All concepts are explained from basic to IIT level, including theory, derivations, numerical problems, objective questions, previous year questions, tough IIT problems, tricks and cautions.
📚 Complete Lesson Index (Part 1 – Part 39)
- Part 1 – Introduction to Work
- Part 2 – Types of Work
- Part 3 – Variable Force & Graphs
- Part 4 – Kinetic Energy
- Part 5 – Work–Energy Theorem
- Part 6 – Potential Energy
- Part 7 – Conservative Forces
- Part 8 – Mechanical Energy
- Part 9 – Power
- Part 10 – Power Applications
- Part 11
- Part 12
- Part 13
- Part 14
- Part 15
- Part 16
- Part 17
- Part 18
- Part 19
- Part 20
- Part 21
- Part 22
- Part 23
- Part 24
- Part 25
- Part 26
- Part 27
- Part 28
- Part 29
- Part 30
- Part 31
- Part 32
- Part 33
- Part 34
- Part 35
- Part 36
- Part 37
- Part 38
- Part 39 – Final IIT Tough Problems & Solutions
Prepared by: Shaktimatha Learning 🌱
Strong Concepts • Smart Practice • Exam Success
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