•The force between two electric dipoles (each of zero net charge) results from the imperfe...

•The force between two electric dipoles (each of zero net charge) results from the imperfect cancellation of the various attractive and repulsive forces among the four charges involved. (a) Prove that the force between the two dipoles in Fig. 1(a) is repulsive. (b) What is it for the dipoles in Fig. 1(b)?

FIGURE 1