### Video Transcript

Which of the following is the
correct unit of electric potential difference? (A) The ampere, (B) the joule, (C)
the newton, (D) the volt, (E) the watt.

To answer this question, we can
consider the SI units shown in the options to see what quantity each unit
measures. A newton is a unit of force. An electric potential difference is
not a force. An electric force is a type of
force, but force is not the same quantity as electric potential difference. A joule is a unit of energy. An electric potential difference is
not a category of energy. There is a category of energy
called electric potential energy, but this energy is not the same quantity as
electric potential difference.

A watt is a unit of power, which is
how much energy is transferred in a time interval. An electric potential difference is
not a category of energy, so it cannot be transferred in a time interval to be a
power measured in watts. An ampere is a unit of electric
current. An electric potential difference is
not an electric current. Electric current is not the same
quantity as electric potential difference.

That leaves the volt. We can recall that the volt is the
unit of electric potential difference. So, we recognize that the correct
answer is (D), the volt.