Question Video: Recognize That Identical Cells Are Connected in Parallel and That Their Total emf Is Equal to the emf of One of the Cells Science

Video Transcript

The diagram shows three cells connected in parallel. What is the total emf provided by the cells?

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 individually.