Gravitation – Phase 3 (Ultimate Objective Mastery)
Page 4D • IIT/JEE Advanced Objective Questions (Q76–Q100)
This page contains extreme-level questions that IIT/JEE uses to separate top 500 ranks from the rest. Most questions are solvable only by thinking + elimination.
Q76. Satellite Suddenly Stops Thrust
A satellite moving in circular orbit suddenly loses engine thrust. What happens to its motion?
Answer: Continues in same circular orbit
Key Insight: Orbit needs velocity, not thrust
Q77. Escape Velocity from Planet Core
Escape velocity from the centre of a uniform planet compared to surface:
Answer: Greater than surface escape velocity
Reason: More work required from centre
Q78. Satellite Energy After Small Tangential Push
A satellite in circular orbit is given a small tangential push. Total energy becomes:
Answer: Less negative
Trap: Energy increases but may remain negative
Q79. g at Poles vs Equator
Acceleration due to gravity is maximum at:
Answer: Poles
Reason: No centrifugal reduction
Q80. Two Satellites, Same Energy
Two satellites have same total energy. Their orbits are:
Answer: Same semi-major axis
IIT Favourite: Energy depends only on semi-major axis
Q81. Field at Earth’s Centre Due to Moon
Gravitational field at Earth’s centre due to Moon is:
Answer: Non-zero
Trap: Symmetry applies only to Earth’s own mass
Q82. Satellite Moving Faster Than Escape Speed
If satellite speed exceeds escape velocity:
Answer: Path becomes hyperbolic
Orbit classification test
Q83. Potential at Centre of Solid Sphere
Gravitational potential at centre of solid sphere is:
Answer: Maximum negative value
Concept: Potential decreases inward
Q84. Satellite Radius Reduced to Half
If orbital radius becomes half, speed becomes:
Answer: √2 times
v ∝ 1/√r
Q85. Gravitational Work Path Dependence
Work done by gravity depends on:
Answer: Initial and final positions only
Conservative force property
Q86. Zero Potential Difference Case
Potential difference is zero when moving:
Answer: On a spherical surface
Equipotential surface
Q87. Satellite Projected Radially Outward
Path followed:
Answer: Straight line (radial)
Angular momentum = 0
Q88. Gravitational Binding Energy Meaning
Binding energy represents:
Answer: Energy required to disperse mass to infinity
Q89. Satellite Speed at Apogee
Compared to circular orbit speed at same radius:
Answer: Smaller
Q90. Field Direction Inside Earth
Direction of gravitational field inside Earth:
Answer: Towards centre
Q91–Q100 (Final Rank-Separators)
- Escape velocity from varying depth
- Energy sign change logic
- Orbit classification by energy
- Field vs potential confusion traps
- Graph-based elimination MCQs
- Assertion–reason extreme cases
- Limiting condition questions
- Multi-statement conceptual sets
- Hidden centre-of-mass logic
- Pure examiner psychology traps
Reality: Very few students attempt all these correctly — and that’s the point.
FINAL PHASE-3 OBJECTIVE MESSAGE
If you understand Q1–Q100, Gravitation becomes a scoring weapon.
Phase 3 • Page 4D (Q76–Q100) Completed 🏆
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