The diagram shows a circuit
consisting of three cells and a resistor. Complete the following
sentence. The three cells are connected in
blank. (A) parallel, (B) series.
They are asking us to decide if the
diagram they’ve shown us is of three cells connected in parallel or in series. There is also a resistor, but it
does not influence how the three cells have been arranged in relation to each
other. And the question only refers to the
three connected cells. Firstly, we are going to remember
what it means for cells to be connected to each other in series or in parallel.
Cells are connected in parallel
when they are situated on different branches of the circuit and the current can flow
from the positive terminal of one of the cells to the opposite negative terminal of
the same cell without having only one choice of path to travel through the other
cells. Essentially, there are multiple
routes for the current to flow, not just one. This is because the cells are not
connected together in a row on the same path. But as we have said, they are on
different branches of the circuit.
Three cells are connected in series
when the positive terminal of one is connected to the negative terminal of the next,
the positive terminal of the second is connected to the negative terminal of the
third, and the current has only one path through all three cells. The cells are not on different
branches; they’re in a row along the same path.
According to the circuit diagram
we’ve been asked to describe, the cells are connected so that the positive terminals
of each cell are connected to the negative terminals of the adjacent ones. The current only has one single
path through which it can travel because the cells are in a row along the same path,
meaning that the three cells in the diagram are connected in series. The correct option to complete the
sentence is option (B) series.