Can Electric Potential Be Understood On Intuitive Level?

[jon4444]

There are two situations with electric potential that confuse me. They're the spots midway between two point charges. If the charges are the same, then the electric field is zero and a test charge would not move if placed there. How can there then be electric potential in that spot?

If charges are opposite, there would be electric field at the mid-way point, a test charge would feel a force and therefore move (and have work done on it?) and yet the electric potential of that spot is zero.

I'm trying to see if there's a simple, intuitive way of understanding this at the High School honors physics (non-calculus) level. Any help appreciated. Thanks,

J

 

[Spinnor]

The forces on the test charge sum to zero only at one point. Move either a positive or a negative test charge a small amount and the force is no longer zero.

 

[Dale]

There are two situations with electric potential that confuse me. They're the spots midway between two point charges. If the charges are the same, then the electric field is zero and a test charge would not move if placed there. How can there then be electric potential in that spot?

The electric potential is flat at that point, but it need not be zero.

If charges are opposite, there would be electric field at the mid-way point, a test charge would feel a force and therefore move (and have work done on it?) and yet the electric potential of that spot is zero.

I'm trying to see if there's a simple, intuitive way of understanding this at the High School honors physics (non-calculus) level.

Think about it like a hill or a topographical map. The height is the potential, the E-field is the gradient of the potential, i.e. the steepness and direction of the slope. So you can have a spot with a high elevation (high potential) that is flat (no E-field) or you can have a spot with elevation 0 (potential is 0) but steeply sloped (large E-field).