Question:
Two charged particles traverse identical helical paths in an opposite sense in a uniform magnetic field
$B=B_{0} \hat{k}$
(a) they have equal z-components of momenta
(b) they must have equal charges
(c) they necessarily represent a particle-antiparticle pair
(d) the charge to mass ratio satisfy: (e/m)1 + (e/m)2 = 0
Solution:
(d) the charge to mass ratio satisfy: (e/m)1 + (e/m)2 = 0