  Form factors are calculated in the point form of relativistic quantum
mechanics for the lowest energy states of a system made of two scalar particles
interacting via the exchange of a massless boson. They are compared to the
exact results obtained by using solutions of the Bethe-Salpeter equation which
are well known in this case (Wick-Cutkosky model). Deficiencies of the
point-form approach together with the single-particle current are emphasised.
They point to the contribution of two-body currents which are required in any
case to fulfil current conservation.
