Electric Potential vs Electric Field?

In summary, the conversation discusses the confusion surrounding the cancellation and addition of components in electric fields and potential. It is noted that in electric fields, the mirrored components cancel out due to it being a vector, but in electric potential, the components are added because it is a scalar. The inconsistency is seen in two different questions, with one question (#25.47) showing the addition of components and the other question (Figure 25.44) stating that the y components cancel out. It is noted that there is no "y component" in the potential as it is a scalar and that the problem should be posted in a homework forum for assistance.
  • #1
Sergio
2
0
I've read that in an electric field due to it being a vector if its mirrored symmetrically the components cancel out. However, the electric potential is a scalar so the components are added not canceled out. This is consistent with one question in my physics H.W., but not for another question. So I'm very confused as to when electric potential cancels out and when it sums up.

The question where it is consistent that the electric potential adds up is # 25.47 here:
http://web.unbc.ca/~hussein/Phys_111_Winter_2005/Selected_Ch25.pdf

However for the following question the y components cancels out according to the answer.

Q.) A uniformly charged insulating rod of length 14.0 cm is bent into the shape of a semicircle as shown in Figure P25.44. The rod has a total charge of 27.50 mC. Find the electric potential at O, the center of the semicircle.

This is figure 25.44 http://www.webassign.net/serpop/p19-21.gif
 
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  • #2
There is no "y component" of the potential since it's a scalar. You just add together or integrate the potential from each source point.
 
  • #3
Khashishi said:
There is no "y component" of the potential since it's a scalar. You just add together or integrate the potential from each source point.

So you always completely disregard 'y' ? Seems wrong.
 
  • #4
Sergio said:
So you always completely disregard 'y' ? Seems wrong.
No, there is no "y component" to disregard, because there is no "y component" to start with. The potential is a scalar, not a vector with x and y components.

Anyway, this a homework-type problem, so it will have to be posted in the homework forum, with an attempt at a solution.

Thread closed.
 

Related to Electric Potential vs Electric Field?

1. What is the difference between electric potential and electric field?

Electric potential is the measure of the electric potential energy per unit charge at a specific point in space, while electric field is the measure of the force per unit charge acting on a test charge at that same point. In other words, electric potential is a scalar quantity that describes the potential energy of a charge, while electric field is a vector quantity that describes the direction and magnitude of the force on a charge.

2. How are electric potential and electric field related?

Electric potential and electric field are closely related, as electric field is the gradient of electric potential. This means that the electric field at a point is equal to the negative gradient of the electric potential at that point. In mathematical terms, this can be expressed as E = -∇V, where E is the electric field, V is the electric potential, and ∇ is the gradient operator.

3. What is the unit of measurement for electric potential and electric field?

The SI unit for electric potential is the volt (V), which is equivalent to joules per coulomb (J/C). The SI unit for electric field is the volt per meter (V/m), which is equivalent to newtons per coulomb (N/C).

4. How do electric potential and electric field affect charged particles?

Electric potential and electric field both play a crucial role in determining the behavior of charged particles. Electric potential determines the potential energy that a particle has at a specific point, while electric field determines the force that will act on the particle at that point. Charged particles will tend to move from areas of high potential to areas of low potential, and will experience a force in the direction of the electric field.

5. How can electric potential and electric field be measured?

Electric potential can be measured using a device called a voltmeter, which measures the potential difference between two points. Electric field can be measured using a device called an electric field meter, which measures the strength and direction of the electric field at a specific point. Both of these measurements can also be calculated using mathematical equations and known values for the charge and distance between the points in question.

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