Four identical compatible 1.5 V cells are connected in parallel. Find total emf.

Solution & explanation

1. All positive terminals join one node and all negative terminals the other.

2. Each branch therefore has the same terminal voltage.

3. Parallel voltage is not the sum of cell emfs.

4. Use the emf of one identical ideal cell.

   $${\epsilon }_{\mathrm{total}}=1.5$$

5. The extra cells can share current and increase capacity under the assumed compatible conditions.

Total emf = 1.5 V