  Dependency on the preparation of state for the Heisenberg uncertainty
principle can be removed with the help of entropy uncertainty principle. The
shortness of the uncertainty principle (UP) can be overcome with the help of
the concept of Shannon's information entropy (SE). In this article, we have
shown that UP in terms of SE holds for a position-dependent effective mass
system. We have considered the Dirac system with a mass-jump at the origin. We
have proved the existence of a lower bound for a UP for this position-dependent
effective mass.
