Lesson 3.7.2.2

3.7.2.2 Gravitational field strength Quiz: AQA Physics, Unit 7

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 3.7.2.2, Gravitational field strength: 20 multiple choice questions for the AQA Physics (7408), Unit 7: Fields and their consequences (A-level only), written with Revision Ninja.

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The 20 questions

  1. What is the definition of gravitational field strength at a point?

    • Energy per unit mass
    • Force per unit mass
    • Force per unit distance
    • Mass per unit force

  2. The gravitational field strength in a radial field at distance r from a mass M is:

    • g = GM / r^2
    • g = GM / r
    • g = G M^2 / r^2
    • g = GM r^2

  3. In which direction do gravitational field lines always point?

    • Towards the mass
    • Away from mass
    • Parallel to orbit
    • Tangential to surface

  4. Why is gravitational field strength approximately constant near Earth's surface?

    • Large Earth mass
    • Constant density
    • Tiny height change
    • High orbital speed

  5. The SI unit of gravitational field strength is:

    • N m^-1
    • N kg^-1, equivalent to m s^-2
    • N s kg^-1
    • kg m^-1

  6. The approximate value of gravitational field strength at the Earth's surface is:

    • 9.8 N kg^-1
    • 9.8 N
    • 98 N kg^-1
    • 0.98 N kg^-1

  7. Outside a uniform planet, how does gravitational field strength vary with distance?

    • Inverse-linear relationship
    • Constant relationship
    • Inverse-square relationship
    • Directly proportional relationship

  8. Gravitational field strength at Earth's surface is 9.8 N kg^-1. What is it at a height where the distance from the centre is twice the radius?

    • about 19.5 N kg^-1
    • about 2.4 N kg^-1
    • about 4.9 N kg^-1
    • about 1.2 N kg^-1

  9. Estimate the gravitational force on a 70 kg person at Earth's surface.

    • about 7.1 N
    • about 140 N
    • about 6900 N
    • about 690 N

  10. Mars has mass 6.4 x 10^23 kg and radius 3.4 x 10^6 m. Estimate the field strength at its surface (G = 6.67 x 10^-11).

    • about 3.7 N kg^-1
    • about 0.37 N kg^-1
    • about 1.6 N kg^-1
    • about 9.8 N kg^-1

  11. An object of mass 500 kg is placed where g = 4.0 N kg^-1. What is its weight?

    • 2000 N
    • 20000 N
    • 125 N
    • 200 N

  12. What is the net gravitational field strength at the midpoint between two equal masses?

    • Double the value
    • Half the value
    • Zero
    • Infinite

  13. A 0.50 kg object experiences a gravitational force of 4.9 N. What is the gravitational field strength at its position?

    • 4.9 N kg^-1
    • 9.8 N kg^-1
    • 0.10 N kg^-1
    • 2.45 N kg^-1

  14. How are gravitational field lines drawn to represent a stronger field?

    • Diverging outwards
    • Farther apart
    • Crossing over
    • Closer together

  15. How does gravitational field strength change if distance from a planet's centre doubles?

    • Unchanged
    • Quadrupled
    • Quartered
    • Halved

  16. Which property of an object remains unchanged when moved from Earth to the Moon?

    • Field strength
    • Weight
    • Mass
    • Potential energy

  17. A planet has the same density as Earth but twice Earth's radius. How does its surface field strength compare with Earth's?

    • twice Earth's
    • half Earth's
    • unchanged
    • four times Earth's

  18. On an Earth-like planet where g = 9.8 N kg^-1 at the surface, estimate g at a distance of 3 times the radius from the centre.

    • about 1.1 N kg^-1
    • about 3.3 N kg^-1
    • about 0.33 N kg^-1
    • about 2.5 N kg^-1

  19. What fundamental property determines the gravitational field strength created by an object?

    • Surface area
    • Velocity
    • Object density
    • Source mass

  20. A graph of g against 1/r^2 for a point mass is a straight line. What is its gradient?

    • M / G
    • G / M
    • GM
    • GM^2

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