Video Transcript
A cell does one joule of work to
separate one coulomb of charge. What potential difference does this
create across the terminals of the cell?
Here, we are asked to find the
potential difference across the terminals of a cell when we are given the amount of
work the cell does in joules and the amount of charge it separates in coulombs.
First, let’s take a look at the
equation for potential difference. The potential difference across the
cell is equal to the amount of work the cell does to separate the charge divided by
the amount of charge that was separated. We can also write this as 𝑉 equals
𝑊 divided by 𝑄, where 𝑉 is the potential difference, 𝑊 is the work done, and 𝑄
is the charge separated.
In this question, we are told that
the cell separates one coulomb of charge, meaning that 𝑄 equals one coulomb. We are also told that one joule of
work is done, so 𝑊 equals one joule. If we substitute these values into
our formula, we find that the potential difference 𝑉 is equal to one joule divided
by one coulomb. This gives us a potential
difference of one joule per coulomb.
Let’s look at these units. Recall that potential difference is
usually measured in units of volts. One volt is equal to one joule per
coulomb. This means that the potential
difference we have just calculated, one joule per coulomb, is equal to one volt. So the potential difference across
the terminals of the cell is equal to one volt. This is our final answer.
