Electric Potential: Dealing with Vectors in Integral Boundaries

AI Thread Summary
The discussion focuses on calculating electric potential using vectors in integral boundaries, specifically the expression V(r) = -∫E·ds. The user is confused about how to incorporate a vector boundary condition, b, when evaluating the potential along the z-direction, given that the electric field E is expressed as a vector. They note that when substituting the boundary b as a magnitude, the result aligns with expected outcomes, but question the necessity of treating b as a vector in this context. The main concern is understanding the relevance of the vector nature of b when the potential is effectively a function of a single component, z. Clarification is sought on the proper treatment of vectors in this integral calculation.
humo90
Messages
13
Reaction score
0
I am confusing about dealing with the vectors in integral boundaries of the electric potential;
^{b}_{a}∫E.ds where a and b are vectors.
For example, if I would calculate the potential for outside region of a sphere along z-direction, I would use E=\frac{ρR^3}{3ε_{0}z^2}\hat{z}, and ds=dz\hat{z}
then V(r)=-^{b}_{∞}∫\frac{ρR^3}{3ε_{0}z^2}\hat{z}.dz\hat{z} = -^{b}_{∞}∫\frac{ρR^3}{3ε_{0}z^2}.dz
After evaluating the integral which would be V(r)=[\frac{ρR^3}{3ε_{0}z}]^{b}_{∞}, say b=b\hat{z}, if I plug in b as magnitude the result would be as usual, but if b is vector, then how could I plug it in this potential function? Please help.
 
Last edited:
Physics news on Phys.org
Why do you plug the vector in it when you have just one component z. It is not V(r) but V(z), so that the vector is not needed.
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...
It may be shown from the equations of electromagnetism, by James Clerk Maxwell in the 1860’s, that the speed of light in the vacuum of free space is related to electric permittivity (ϵ) and magnetic permeability (μ) by the equation: c=1/√( μ ϵ ) . This value is a constant for the vacuum of free space and is independent of the motion of the observer. It was this fact, in part, that led Albert Einstein to Special Relativity.
Back
Top