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NEET Gravitation: 5 practice MCQs with answers

By the PrepMatic team · Updated 9 Oct 2026 · 3 min read

Gravitation is one of the most formula-driven chapters in NEET Physics, and one of the most predictable. The questions are usually ratios: how g changes with height or depth, how escape velocity compares with orbital velocity, or what Kepler's third law gives for a new planet. The five MCQs below cover those cases at NCERT Class 11 level.

What this chapter covers in the NEET syllabus

Gravitation is its own NMC unit and a Class 11 NCERT chapter. The topics are:

• Newton's universal law of gravitation and the gravitational constant G.
• Acceleration due to gravity, and its variation with altitude, depth and latitude.
• Gravitational field, potential and potential energy.
• Escape velocity.
• Motion of a satellite: orbital velocity, time period and energy.
• Kepler's three laws of planetary motion.

Five practice MCQs on Gravitation

Question 1

If g is the acceleration due to gravity at the Earth's surface, its value at a height equal to the radius of the Earth, R, above the surface is:

• A. g/2
• B. g/8
• C. g/4
• D. g/√2

Question 2

The ratio of the escape velocity from the Earth's surface to the orbital velocity of a satellite orbiting very close to the surface is:

• A. 1/√2
• B. 1
• C. 2
• D. √2

Question 3

A planet orbits the Sun at a distance 4 times that of the Earth. Its time period in Earth years is:

• A. 16 years
• B. 64 years
• C. 8 years
• D. 4 years

Question 4

At a depth of R/2 below the Earth's surface, assuming uniform density, the acceleration due to gravity is:

• A. g/2
• B. g/4
• C. 3g/4
• D. zero

Question 5

A planet has 8 times the mass of the Earth and twice its radius. The acceleration due to gravity at its surface, in terms of the Earth's value g, is:

• A. g
• B. 2g
• C. 4g
• D. 8g

Answers and explanations

1. C. At height h, g' = g R²/(R + h)². With h = R the distance from the centre is 2R, so g' = g/4. Students often answer g/2 by adding R and forgetting to square.
2. D. Escape velocity is √(2gR) and orbital velocity near the surface is √(gR). The ratio is √2, which is why a satellite given an extra 41% of its orbital speed can escape.
3. C. Kepler's third law says T² is proportional to r³. If r is 4 times the Earth's, T² = 4³ = 64 in units of years squared, so T = 8 years.
4. A. Inside the Earth, g' = g(1 − d/R). With d = R/2, g' = g(1 − ½) = g/2. At the centre (d = R) it is zero.
5. B. Since g = GM/R², the new value is g × (8)/(2²) = g × 8/4 = 2g.

How to prepare Gravitation

• Memorise a short list of results and what they depend on. g = GM/R²; orbital velocity √(GM/r); escape velocity √(2GM/R); time period T = 2π√(r³/GM). Most questions are ratio problems on these, so identify which quantity is held constant and which varies.
• Learn the energy of a satellite. Potential energy is −GMm/r, kinetic energy is GMm/2r, and total energy is −GMm/2r. The negative total energy is what "bound" means.
• Compare how g varies. It falls as 1/r² above the surface, falls linearly with depth inside the Earth, and is slightly lower at the equator than at the poles. Draw the g versus distance graph once, with its peak at the surface.
• Know Kepler's laws in words. Orbits are ellipses with the Sun at a focus, the radius vector sweeps equal areas in equal times, and T² is proportional to a³. The second law is angular momentum conservation, which links to Rotational Motion.
• Stay careful with units. Use metres and kilograms with G = 6.67 × 10⁻¹¹ N m² kg⁻² unless the question gives ratios.

Because many questions are ratios, this chapter responds well to speed drills: set a timer and solve 10 ratio problems in 10 minutes. See the NEET Physics preparation guide for where this fits in the full plan, and the NEET syllabus for the unit list.

Take a full Gravitation test on PrepMatic

Because Gravitation questions are mostly ratio problems, a short timed test shows quickly whether your formulas are secure. PrepMatic's topic tests run about 15 questions in 30 minutes with NEET's negative marking, and the free Basic plan includes them. More chapters are on the practice hub.

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