Video Transcript
Four identical cells are connected
in parallel. Each cell provides an emf of three
volts. What is the total emf provided by
the cells if they are all aligned in the same direction?
Let’s start by drawing a diagram of
the circuit. We see that there are four
identical cells connected in parallel with the positive terminals in the same
direction, and each cell produces an emf of three 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 can 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, C, and D.
Across each path, there is the same
potential difference, three volts. So the potential difference between
point one and point two must be three volts. As the potential difference between
these points is three volts, the total emf supplied by all the cells combined in
parallel must be three volts, the same potential difference as for each of the cells
individually.
