For the below figure, find the total voltage when the batteries are connected in series.
25 volts
In the circuit diagram, the cells are connected in series.
In a series connection of cells, the total potential difference will be the sum of potential differences of all the individual cells.
Effective potential difference = V1+ V2+ V3+ V4+ V5
Effective potential difference = 5 V +7 V +8 V +4.2 V +0.8 V = 25 V.