Video Transcript
Which of the following diagrams
shows three cells connected in parallel?
The problem asks us to decide which
of the two diagrams is of three cells connected in parallel. To find the answer, let us remember
that cells are connected in parallel when there are multiple paths that connect the
positive and negative terminals of each cell and the cells sit on separate branches
of the circuit.
In figure 1, all the cells are
drawn in parallel with multiple paths connecting the positive and negative
terminals. In figure 2, we can see the same
thing, but the paths have been drawn as straight lines and the branches of the
circuit are a little easier to see. In the case where there is only one
path between the terminals of a cell, then they will be in series.
Now, we are in a position to
analyze the diagrams we’ve been given. And we can see that in option (A),
there is a single path between the positive terminal of cell A, which is connected
to the negative terminal of cell B. And in turn, the positive terminal
of cell B is connected to the negative terminal of cell C. So, with only one path connecting
all of them, these three cells are connected in series.
If we look at option (B), we can
see that there are three branches of the circuit with one cell on each branch. The positive terminal of cell A is
connected to the positive terminals of cells B and C. And the current can go from the
positive terminal of cell A to the negative terminal of cell A through path one or
path two. Also, the positive terminal of cell
B is connected to its opposite negative terminal through paths three and four. And the positive terminal of cell C
is connected to its opposite negative terminal through paths five and six.
So, because the current can go from
one terminal to its opposite terminal in each cell through different routes, we can
say that these cells are connected in parallel. So we can conclude that the correct
option is (B), showing three cells connected in parallel.
