GravitationNEET MCQs with solutions
Gravitation covers Newton's law of gravitation, gravitational field and potential, Kepler's laws, orbital velocity, escape velocity and variation of g with height/depth. NEET tests orbital mechanics, escape velocity, variation of g and gravitational PE — both conceptual and numerical.
- Class
- 11 Physics
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- 24 questions
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- 468 questions
- ELITE questions
- 34
- NCERT topics
- 13
Practise 24 questions
Tap an option to check it. Questions from every NCERT topic in this chapter, from easy to hard.
Q1Mixed Revision
The gravitational field intensity at Earth's centre is:
Not quite — the answer is B.
At Earth's centre, mass is symmetrically distributed in all directions. Gravitational pulls from all sides cancel exactly, giving zero net field. This differs from gravitational potential, which is most negative (−3GM/2R) at the centre.
Q2Variation of g
The value of acceleration due to gravity decreases with altitude because:
Not quite — the answer is A.
g = GM/r². As r increases with altitude, g falls as 1/r². G and M remain constant; confusing them with altitude-dependent changes is the most common error.
Q3Grand Test
A planet is at aphelion in its elliptical orbit. Which quantity is minimum there?
Not quite — the answer is A.
At aphelion the planet is farthest, so by Kepler's Second Law it moves slowest — orbital speed is minimum. Distance from Sun is maximum at aphelion, not minimum. Angular momentum is conserved throughout and has no minimum point.
Q4Gravitational Potential Energy
Gravitational potential energy of two point masses separated by a finite distance is always:
Not quite — the answer is A.
U=−GMm/r. With U=0 at infinity as reference, U is always negative at finite separation. Unlike electric PE, gravity is always attractive — there is no repulsive case that could make U positive.
Q5Universal Law of Gravitation
Who proposed the Universal Law of Gravitation stating that every particle attracts every other particle with a force proportional to the product of their masses and inversely proportional to the square of the distance between them?
Not quite — the answer is A.
Newton formulated the Universal Law of Gravitation in 1687. Kepler described planetary motion empirically but never derived the force law linking it to mass and distance.
Q6Acceleration Due to Gravity (g)
Acceleration due to gravity at Earth's surface is directed:
Not quite — the answer is A.
g is the gravitational acceleration produced by Earth's pull, always directed toward Earth's centre. It is not related to the rotation axis or tangential to the surface.
Q7Earth Satellites
An artificial satellite revolves around the Earth primarily because:
Not quite — the answer is D.
Gravity is the sole reason a satellite stays in orbit — it continuously provides the centripetal force for circular motion. The common misconception that gravity is absent in space is false; gravity is fully present and responsible for the orbit.
Q8Kepler's Laws
Kepler's First Law states that planets move around the Sun in:
Not quite — the answer is A.
Every planet revolves in an ellipse with the Sun at one focus, not the centre. Circular orbits are a special case only; parabolic and hyperbolic paths are unbound trajectories, not planetary orbits.
Q9Orbital Velocity
Orbital velocity is defined as the minimum horizontal velocity required for a satellite to maintain a stable circular orbit around Earth. This statement is:
Not quite — the answer is A.
Orbital velocity is exactly the minimum horizontal speed for stable circular orbit at a given radius. Students confuse this with escape velocity, which is the minimum speed to leave Earth's gravity entirely.
Q10Energy of Satellite
The total mechanical energy of a satellite in a circular orbit is always:
Not quite — the answer is A.
Total energy = KE + PE = GMm/2r − GMm/r = −GMm/2r, which is always negative for a bound orbit. Students confuse this with the escape condition where total energy is exactly zero.
Q11Geostationary Satellite
A geostationary satellite revolves around Earth with a time period of:
Not quite — the answer is A.
A geostationary satellite has orbital period equal to Earth's rotation period of 24 hours. Students confuse this with 12-hour navigation satellites like those in GPS constellations.
Q12Escape Speed
Escape speed is the minimum speed required for a body to:
Not quite — the answer is B.
Escape speed is the minimum speed to reach infinity with zero final KE, needing no further propulsion. Students confuse it with orbital speed (Option A), which requires sustained centripetal condition.
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Get RankUp on Google PlayQ13Gravitational Constant (G)
The universal gravitational constant G is numerically equal to the gravitational force between two point masses each of 1 kg separated by 1 m. The value of G in SI units is:
Not quite — the answer is D.
From F = Gm₁m₂/r² with m₁=m₂=1 kg and r=1 m, F = G numerically. G ≈ 6.67×10⁻¹¹ N m² kg⁻². Option A (9.8) is g, the acceleration due to gravity — the most common confusion.
Q14Universal Law of Gravitation
The gravitational force between two point masses is directly proportional to:
Not quite — the answer is B.
F = Gm₁m₂/r² shows direct proportionality to the product m₁m₂. Choosing sum of masses is the most common error, confusing additive with multiplicative dependence.
Q15Universal Law of Gravitation
Two masses are separated by distance r. If the distance becomes 2r while masses remain unchanged, the gravitational force becomes:
Not quite — the answer is C.
F' = Gm₁m₂/(2r)² = F/4 by the inverse-square law. Students confusing inverse with inverse-square incorrectly choose half the original force.
Q16Universal Law of Gravitation
Two bodies of masses 4 kg and 9 kg are separated by 3 m. Taking G = 6.67 × 10⁻¹¹ N m² kg⁻², the gravitational force between them is closest to:
Not quite — the answer is D.
F = (6.67×10⁻¹¹ × 4 × 9)/9 = 2.67×10⁻¹⁰ N. Option A arises from forgetting to square r; option B from dividing by r instead of r².
Q17Universal Law of Gravitation
What is the direction of gravitational force between two point masses?
Not quite — the answer is A.
Gravitational force is always attractive and acts along the line joining the masses, making it a central force. Unlike electrostatic force, gravity has no repulsive counterpart in classical physics.
Q18Universal Law of Gravitation
Which of the following statements about gravitational force are correct? I. It is a central force. II. It acts along the line joining two masses. III. It obeys the inverse-square law. IV. It depends on the medium between the masses.
Not quite — the answer is B.
Statements I, II, III are correct. Gravitational force is independent of the intervening medium — unlike electrostatic force, which is reduced in a dielectric medium. Statement IV is false.
Q19Universal Law of Gravitation
Which of the following correctly describes the universal gravitational constant G?
Not quite — the answer is C.
G is a universal constant — its value 6.67×10⁻¹¹ N m² kg⁻² does not change with location, medium, or the nature of the bodies. Option D is the most tempting trap: g changes with location, but G does not.
Q20Universal Law of Gravitation
All of the following statements about gravitational force are correct EXCEPT:
Not quite — the answer is D.
Gravitational force is entirely independent of electric charge — it depends only on mass. Confusing Coulomb's law (charge-dependent) with Newton's law of gravitation is the targeted error here.
Q21Universal Law of Gravitation
Three equal masses m are placed at the vertices of an equilateral triangle of side a. The net gravitational force on any one mass due to the other two is directed:
Not quite — the answer is A.
The two equal forces from the other vertices are symmetric about the angle bisector. Their resultant lies along the bisector directed toward the centroid. Net force magnitude is √3 Gm²/a².
Q22Universal Law of Gravitation
Two masses exert gravitational forces on each other. Which relation is always true regardless of the individual mass values?
Not quite — the answer is A.
By Newton's Third Law, the gravitational pull on m₁ due to m₂ equals in magnitude the pull on m₂ due to m₁, regardless of the ratio of masses. Option B is the most common misconception.
Q23Universal Law of Gravitation
Two point masses m and 2m are separated by distance r. If both masses are doubled and the distance is also doubled, the new gravitational force compared to the original is:
Not quite — the answer is B.
Original F = 2Gm²/r². New F' = G(2m)(4m)/(2r)² = 8Gm²/4r² = 2Gm²/r² = F. The ×4 increase in mass product is exactly cancelled by the ×4 increase from doubling r. Option A (4F) is chosen by students who forget to square the new distance.
Q24Universal Law of Gravitation
Two identical masses attract each other with force F. If one mass is tripled while the other and the distance remain unchanged, the gravitational force becomes:
Not quite — the answer is C.
F ∝ m₁m₂, so tripling one mass triples the product and hence the force: F' = 3F. Option D (9F) is the trap — it would apply if both masses were tripled simultaneously.
ELITE question · AIR under 50 level
This chapter has 34 ELITE questions for students aiming at the very top. They are only in the app.
Unlock ELITE questions in the appKey Gravitation Formulas
Quick revision: most questions in this chapter test these facts.
| Concept | Key Formula |
|---|---|
| Newton's law | F = GMm/r²; gravitational constant G = 6.674 × 10⁻¹¹ N m² kg⁻² |
| g at height h | g' = g(1 − 2h/R) for h << R; g' = gR²/(R+h)² for large h |
| g at depth d | g' = g(1 − d/R); zero at centre |
| Orbital velocity | v₀ = √(gR) ≈ 7.9 km/s for Earth orbit near surface |
| Escape velocity | vₑ = √(2gR) = √2 × v₀ ≈ 11.2 km/s for Earth |
| Kepler's 3rd law | T² ∝ a³; relates orbital period to semi-major axis |
What the app covers in this chapter
468 questions in total, each with a detailed explanation.
| Mixed Revision | 69 |
| Variation of g | 55 |
| Grand Test | 52 |
| Gravitational Potential Energy | 40 |
| Universal Law of Gravitation | 38 |
| Acceleration Due to Gravity (g) | 38 |
| Earth Satellites | 37 |
| Kepler's Laws | 30 |
| Orbital Velocity | 25 |
| Energy of Satellite | 24 |
| Geostationary Satellite | 23 |
| Escape Speed | 19 |
| Gravitational Constant (G) | 18 |
Questions students ask
Is Gravitation important for NEET?
Yes — orbital velocity, escape velocity, variation of g and Kepler's laws are tested regularly. Both formula-based and conceptual questions appear.
Which topics should I revise first?
Focus on variation of g with height and depth, orbital and escape velocity formulas, Kepler's three laws, and gravitational potential energy (−GMm/r).
How many questions from this chapter are on RankUp?
The RankUp app has 468 questions on Gravitation, including 34 ELITE questions. Every question has a detailed explanation.
