### Video Transcript

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

First, let’s recall that emf is
another name for potential difference. And it’s given in volts,
specifically the voltage listed by each cell. So the emf provided by the first
cell is three volts, by the second cell is six volts, and by the third cell is two
volts. Now, we are looking for a total
emf, and it is a total emf from cells connected in series. We can do this by recalling that to
find the total emf provided by a series combination of cells, we simply add up all
of the emfs from each cell. So the total emf in the diagram we
are given is three volts plus six volts plus two volts.

Remember that when we add
quantities with the same units, we add the numbers and keep the units. So three volts plus six volts is
three plus six, which is nine volts. Using the same idea, nine volts
plus two volts has units of volts. And the number is nine plus two,
which is 11. So the series combination of cells
in the diagram provides a total emf of 11 volts.