Register to reply 
Electric Potential Concept Question 
Share this thread: 
#1
Feb911, 02:06 PM

P: 32

Why is the electric potential in the middle of two oppositely charged points 0? Does this also mean that there's no potential energy at this point?



#2
Feb911, 06:27 PM

PF Gold
P: 3,080

Remember that all potentials work by looking at how they vary from place to place absolute values at a given place are never of any physical importance. So when we take zero at the center, it's just a convenient convention.



#3
Feb911, 07:46 PM

P: 32

Alright... That's somewhat counterintuitive for me.
So does that mean that if I move a charge from infinity to the middle of the two opposite charges, no net work would be done? 


#4
Feb911, 08:29 PM

PF Gold
P: 3,080

Electric Potential Concept Question
That is also true it means that if we set the potential at infinity to be zero, that's the same convention as setting it to be zero at the center. You can tell that has to be true from the symmetryif the charges are equal and opposite, what is going to be the sign of the potential at the center, relative to infinity? Which sign could possibly be singled out?



#5
Feb911, 09:05 PM

P: 32

Shouldn't it have the exact same value as the potential at infinity?



#6
Feb1011, 12:53 AM

PF Gold
P: 3,080

Yes, by symmetry if it were to deviate from the value at infinity, the deviation would need a sign, and we should be able to reverse that sign by reversing the sign of the charges, but such a reversal is just a left/right reflection.



Register to reply 
Related Discussions  
Electric potential and electric potential energy concept questions  Introductory Physics Homework  3  
Concept of Potential Energy vs Electric Potential in an EField  Introductory Physics Homework  1  
Electric Potential concept  Electrical Engineering  8  
Concept Question  Electric Potential, and Electric Fields  Introductory Physics Homework  8  
Quick Electric Potential Concept Question  Introductory Physics Homework  6 