Relationship between density of energy and magnetic force

AI Thread Summary
The discussion focuses on the relationship between energy density in a magnetic field and magnetic force, specifically using the formula F = q v X B. The energy density of a magnetic field is given by the equation (B_0)² / (2μ). To find the magnetic force from a known energy density, one can solve for B using the energy density formula and then substitute that value into the force equation. This approach allows for calculating the magnitude of the magnetic force based on energy density. Understanding this relationship is crucial for applications in electromagnetism and physics.
ash misty
Messages
2
Reaction score
0
What is the relationship between density of energy stored in a magnetic field and the magnetic force?
 
Physics news on Phys.org
F = q v X B

Homework: Look up the energy density of a magnetic field.
 
The energy of a density field is ((B_0)^{2}) / (2\mu). I am looking for a direct formula as such linking these two. Let's say I have the value for density of energy, how can we find the magnetic force?
 
Solve the energy density for B. Then substitute that into the expression for F. Note, you will only be able to solve for the magnitude.
 
This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'
Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...

Similar threads

Back
Top