Question

Consider two charged particles 1 and 2, each of them able to translate (move from place to place) and to spin. In which of the following circumstances is there a magnetic interaction between the particles:

(a) neither particle translating, nei- ther particle spinning;

(b) neither translating, only particle 1 spinning;

(c) neither translating, both spinning;

(d) 1 at rest and not spinning, 2 translating and not spinning;

(e) 1 at rest and not spinning, 2 translating and spinning;

(f ) 1 spinning and not translating, 2 translating and not spinning;

(g) 1 spinning and not translating, 2 translating and spinning;

(h) both translating, neither spinning;

(i) both translating, only 2 spinning;

(j) both translating, both spinning.