A charge of #4 C# is passing through points A and B on a circuit. If the charge's electric potential changes from #32 J# to #9 J#, what is the voltage between points A and B?

1 Answer
Jan 19, 2016

Answer:

A volt is defined as a joule per coulomb, #V=E_e/Q#. In this case, #V=(32-9)/4 = 5.75 V#

Explanation:

A volt is a unit of electric potential. A joule is a measure of electric potential energy. A volt is defined as a joule per coulomb: if 1 coulomb #(C)# of charge is moved through a potential difference of 1 volt #(v)#, its electric potential energy will change by 1 joule #(J)#.

In this case #4 C# of charge moved such that its electric potential energy changed by #32-9=23 J#. We are asked for the potential difference in volts between the two points.

#V=(32-9)/4 = 5.75 V#

(Note: The question is phrased imprecisely, since 'electric potential' should be measured in volt and 'electric potential' energy in joule)