Current Sources in Series

The current through any branch of a network can be only single-valued. For the situation indicated at point a in Fig.no.1, we find by application of Kirchhoff's current law that the current leaving that point is greater than that entering—an impossible situation.
Fig.no.1:
Therefore,
current sources of different current ratings are not connected in series,
just as voltage sources of different voltage ratings are not connected in parallel.