Relation between current and flux

AI Thread Summary
Voltage is proportional to the negative change in magnetic flux, indicating that the voltage graph represents the negative derivative of the flux graph. In motors, a change in flux induces a current that generates an opposing magnetic field, suggesting a direct relationship between flux and current. The equation Φ=LI illustrates that flux is proportional to current, with L representing the coil's inductance as a constant. Current and flux will have similar shaped graphs over time, provided there is no magnetic saturation. This relationship highlights the interconnectedness of voltage, current, and magnetic flux in electrical systems.
TT0
Messages
210
Reaction score
3
So I learned that voltage/emf is proportional to the negative change in flux so the graph of the voltage is the negative derivative of the flux graph.

What is the relation between flux and current. In a motor, a change in flux induces a current that creates an opposing magnetic field, and since current is proportional to magnetic field strength, does that mean flux is proportional to current in the coil. So does this mean current and flux will have a similar shaped graph over time?

Thanks
 
Physics news on Phys.org
I didn't follow your motor example. Which motor are you talking about?
TT0 said:
So does this mean current and flux will have a similar shaped graph over time?
Yes, but only if there is no magnetic saturation.

Φ=LI, where L is the inductance of the coil, which is a constant.
So, flux∝current.
 
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