Electric field and electric potential

In summary, the conversation discusses the relationship between electric potential and electric field. It is mentioned that while potentials add like numbers, fields add like vectors and two fields of equal magnitude can cancel each other out if pointed in opposite directions. The conversation also involves assigning signs to charges and finding the overall potential at a designated point. The final solution is determined to be A=F>B=C=D=E.
  • #1
vysero
134
0

Homework Statement



Untitled.png
[/B]

Homework Equations



dV = -EdX[/B]

The Attempt at a Solution



Well I was trying to think about the relationship between E and V. So I believe the two V and E are co dependent. So in a situation where the distance and the potential are not changing then wouldn't V just be equal to -E? If that is correct then: D>E>A>F=C>B is the answer.[/B]
 
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  • #2
The difference is that while potentials add like numbers, fields add like vectors. That's because potential is a scalar quantity while fields are vector quantities. Two fields of equal magnitude can cancel each other out simply by being pointed in opposite directions.
 
  • #3
gneill said:
The difference is that while potentials add like numbers, fields add like vectors. That's because potential is a scalar quantity while fields are vector quantities. Two fields of equal magnitude can cancel each other out simply by being pointed in opposite directions.

I didn't think about that is my answer correct though?
 
  • #4
vysero said:
I didn't think about that is my answer correct though?
Nope. You'll have to go through the diagram and assign some signs to the charges that work for the potential given, then add up the field contributions (as vectors).
 
  • #5
gneill said:
Nope. You'll have to go through the diagram and assign some signs to the charges that work for the potential given, then add up the field contributions (as vectors).

I am a little confused like for case B if I say all are + and I know the value of the charges are say q for each then E is going to be zero for the point x right because all the vectors cancel. However, using that logic on case F confuses me. The two cases seem to be similar but the charges would have to be different than say q like in case B but the directions say all the charges are the same.

Something else that still confuses me is assigning signs to the charges. Like I know how to figure out the over-all pe of a system of particles but not of a system at a designated point.
 
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  • #6
vysero said:
I am a little confused like for case B if I say all are + and I know the value of the charges are say q for each then E is going to be zero for the point x right because all the vectors cancel. However, using that logic on case F confuses me. The two cases seem to be similar but the charges would have to be different than say q like in case B but the directions say all the charges are the same.
The charges all have the same magnitude but may have different signs. Case F can be solved with the correct application of signs to the charges. You know that the net potential at the origin is positive, so there must be an excess of positive charges in the scenario. So start with them all positive and then change one... If nothing else you could try trial and error :)
Something else that still confuses me is assigning signs to the charges. Like I know how to figure out the over-all pe of a system of particles but not of a system at a designated point.

The potential in this case is the electric potential (Volts). Any point in space has an electric potential due to the net effect of all the charges that exist. Fortunately most of them cancel out!
 
  • #7
Okay so here is what I am thinking now:

A=F>B=C=D=E

is that correct?
 
  • #8
I have to say that I'm not keen on just validating what could be guesswork without seeing the details of the work. But I get the feeling that you've put in the effort and understood what you're doing. So in this instance I will confirm that your answer is good :)
 
  • #9
gneill said:
I have to say that I'm not keen on just validating what could be guesswork without seeing the details of the work. But I get the feeling that you've put in the effort and understood what you're doing. So in this instance I will confirm that your answer is good :)

Thank you for your help!
 

1. What is an electric field?

An electric field is a physical quantity that describes the influence one electrically charged object has on another. It is a vector quantity, meaning it has both magnitude and direction, and is measured in units of force per unit charge (N/C or V/m).

2. How is electric field different from electric potential?

Electric field and electric potential are related but different concepts. Electric field is a measure of the force experienced by a charged particle at a given point, while electric potential is a measure of the energy that a charged particle has at a particular location in an electric field.

3. How is electric potential calculated?

Electric potential is calculated using the equation V = kQ/r, where V is the electric potential, k is the Coulomb constant, Q is the magnitude of the charge, and r is the distance from the charge.

4. What are some real-world applications of electric fields and electric potential?

Electric fields and electric potential have many practical applications, including powering electronic devices, generating electricity, and controlling the movement of charged particles in medical equipment such as MRI machines.

5. How do electric fields and electric potential affect the behavior of charged particles?

Electric fields and electric potential play a crucial role in determining the behavior of charged particles. They can cause particles to accelerate, change direction, or be attracted or repelled by other charged particles. The strength and direction of the electric field and electric potential at a given point determine the behavior of charged particles at that location.

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