  Students often have difficulty in understanding qualitatively the behaviour
of simple electric circuits. In particular, as different studies have shown,
they find multiple batteries connected in multiple loops difficult to analyse.
In a recent paper [Phys. Educ. 50 568 (2015)], we showed such an electric
circuit, which consists of ideal batteries connected in parallel, that couldn't
be solved by the existing circuit analysis methods. In this paper, we shall
introduce a new mathematical method of solving simple electric circuits from
the solutions of more general circuits and show that the currents, in this
particular circuit, take the indeterminate 0/0 form. We shall also present some
of the implications of teaching the method. We believe that the description
presented in this paper should help the instructors in teaching the behaviour
of multiple batteries connected in parallel.
