10 minutes maximum! Can you do it in 5?

 1. Electrical potential Ve is given by the equation:-

Which of these is the unit given for Ve?

  • A. joule per second
  • B. joule per kilogram
  • C. coulomb
  • D. volt

2. Which of these diagrams correctly shows the electric field pattern around a single negative charge like an electron?


3. Which of these diagrams shows the electric field between 2 identical positive charges? (Only a few key field lines have been shown).

4. At the point directly in the centre of the two positive charges q shown in question 3, the distance from each charge is r.
What is the electric field strength E and the electrical potential Ve?
E Ve
zero zero

5. Gravitational and electrical fields have 'equipotential surfaces'. These are always..

  • A. ..equally spaced.
  • B. ..perpendicular to field lines.
  • C. ..circular.
  • D. ..measured in units of energy.


6. The graph below shows how a quantity (x) varies with distance (r) from an object. In this graph x is inversely proportional to -r.

x ∝ - 1

This could be a graph showing....

  • A. ..gravitational potential with distance r from a planet.
  • B. ..electric field strength from a point charge.
  • C. ..the kinetic energy with distance r for a body in orbit around a planet.
  • D. ..electric potential from a point positive charge.

7. A space ship is projected along the Moon's surface at high speed and then projected into space. It requires an escape velocity of v.

To reach deep space from a moon with no atmosphere, the same mass but four times the radius will require a velocity of:

The Moon
  • A. v/4
  • B. v/2
  • C. 2v
  • D. 4v

8. A body of mass m is in orbit at a distance r around a planet of mass M.
The kinetic energy Ek of the body is:

9 & 10. The gravitational potential at the surface of the Moon is -2.8 MJ kg-1. Moon's surface

9. This means that if a 10 kg rock is lifted from the Moon's surface into space:

  • A. 28 MJ of energy is released.
  • B. 28 MJ of energy is required.
  • C. 0.28 MJ of energy is released.
  • D. 0.28 MJ of energy is required.

10. To calculate the gravitational energy increase for this rock over a small height increase Δr, the formula required is: