A charge of #4 C# is passing through points A and B on a circuit. If the charge's electric potential changes from #27 J# to #3 J#, what is the voltage between points A and B?

1 Answer
Feb 1, 2016

If a charge #Q# passes through the points #A# and #B#; and the difference of the electric potential between points #A# and #B# is #DeltaW#. Then the voltage #DeltaV# between the two points is given by:

#DeltaV=(DeltaW)/Q#

Let the electric potential at point #A# be denoted by #W_A# and let the electric potential at point #B# be denoted by #W_B#.

#implies W_A=27J# and #W_B=3J#

Since the charge is moving from #A# to #B# therefore the difference of electrical potential between points can be found out by:
#W_B-W_A#
#=3J-27J=-24J#

#implies DeltaW=-24J#

It is given that charge #Q=4C#.

#implies DeltaV=(-24J)/4=-6#Volt

#implies DeltaV=-6#Volt

Hence, the voltage between points #A# and #B# is #-6#Volt.

Any one who thinks that my answer is incorrect please tell me.