When is the Electric Potential 0

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The electric potential is defined relative to a reference point, commonly set to zero at infinity. It is not necessarily zero where the electric field is zero, as potential can remain constant without changing. The potential can also be defined as zero near a smaller charge, depending on the context. Grounding a conductor means it is held at a defined potential of zero. Understanding electric potential requires recognizing that it is a relative measure rather than an absolute one.
Katran0595
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Homework Statement


The question asks: Where is the electric potential 0?

Homework Equations


I believe the relevant equations are v=1/(4*pi*epsilon) (Q/r) or v=-Ed

The Attempt at a Solution


I think that the electric potential is 0 when the electric field is zero as well. However, I am not quite sure which equations to look at exactly or if an equation is necessary. Some answers state that the electric potential is zero when it is near the smaller charge or it is zero when the point is at infinity.
 
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Katran0595 said:

Homework Statement


The question asks: Where is the electric potential 0?

Homework Equations


I believe the relevant equations are v=1/(4*pi*epsilon) (Q/r) or v=-Ed

The Attempt at a Solution


I think that the electric potential is 0 when the electric field is zero as well. However, I am not quite sure which equations to look at exactly or if an equation is necessary. Some answers state that the electric potential is zero when it is near the smaller charge or it is zero when the point is at infinity.

Welcome to the PF.

Is there a figure that goes along with this question? Can you scan it or describe it? :smile:
 
berkeman said:
Welcome to the PF.

Is there a figure that goes along with this question? Can you scan it or describe it? :smile:
Unfortunately there is no figure. The professor just asked us the general question :(
 
It is nothing to do with the field's being zero. Where the field is zero, that just means the potential is not changing there, in any direction.
Potential, whether electric or gravitational, is a relative matter. That is why we usually speak of potential difference. You can set any point to be at zero potential, and determine potentials elsewhere in relation to it. In particular, when we say that some conductor is grounded, we just mean that it is held at the potential we are defining as zero.
That said, a usual convention is to say that the potential at infinity is zero.
 
"Potential energy" is always relative to some given point. You can choose the potential energy to be 0 at any given point by choosing to calculate it relative to that point.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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