Correct Answer - C
From the circuit diagram, it is clear that `3V` battery and 4 V battery are in series, and hence, that net e.m.f of these two is `(3+4) V =7 V` and these two are in parallel with 7V battery. We know that when identical electric cells are connected in parallel combination the total e.m.f will be equal to the e.m.f of any one of the cell, and hence, the e.m.f in the circuit is 7V.
