The picture shows the circuit
symbol for a cell. Which line represents the positive
terminal of the cell?
Here, we’re given a diagram of a
cell from an electric circuit and we’ve been asked which line, the shorter or longer
one, represents the positive terminal of the cell.
To answer this, let’s recall that
conventional electric current always points away from the longer line and toward the
shorter line of the cell. We should also remember that
conventional current was defined under the assumption that current is the flow of
positive charge carriers. Because of this, conventional
electric current points away from the positive terminal and toward the negative
Now, we can clearly see that
conventional current points away from the positive terminal, which is represented by
the longer line. Therefore, it’s the longer line
that represents the positive terminal of the cell.