1) X and Y are two identical conducting spheres separated by a distance d. X has a charge +6.0 μC and Y has a charge –2.0 μC. The electric force on Y is −F (i.e. attractive).

The spheres are touched together and are then returned to their original separation d.

What is the force on Y now nearest to?

2) The diagram shows an insulating rod with equal and opposite point charges at each end.

An electric field of strength E acts on the rod in a downwards direction.

Which row is correct?

3) Two oppositely-charged parallel plates are arranged as shown.

An electron is released from rest from the surface of the negatively-charged plate. The electron travels from the negatively-charged plate towards the positively-charged plate.

Which graph shows how the force F on the electron varies with its distance x from the negative plate?

4) The electric field at a certain distance from an isolated alpha particle is 3.0 × 10⁷ N C^–1.

What is the force on an electron when at that distance from the alpha particle?

Take the magnitude of the charge of the electron to be 1.60 × 10⁻¹⁹ C.

5) The force of attraction between two unlike charges is 1.5 N. If the distance between the charges is doubled, what is the force of attraction between them?