The diagram shows three cells
connected in parallel. What is the total emf provided by
We see that there are three
identical cells connected in parallel with the positive terminals in the same
direction, and each cell produces an emf of nine volts. The question asks for the total emf
provided by the cells.
To find the total emf, we must
measure the potential difference between point one and point two. By doing this, we can find the
total emf from all the cells. We see that the possible paths from
the negative to the positive terminals of each cell pass through points one and two
along paths A, B, and C. Across each path, there is the same
potential difference, nine volts. So the potential difference between
point one and point two must be nine volts.
As the potential difference between
these points is nine volts, the total emf supplied by all the cells combined in
parallel must be nine volts, the same potential difference as for each of the cells