- #1
TheJfactors
- 14
- 0
I see a lot of problems on constant current inducing a current in another wire due to its associated magnetic field, but not so much a single wire's induced electric field. If the current along an infinitely long wire is flowing out of the page and inducing a counter-clockwise spinning magnetic field, what happens when the current continues to increase in magnitude with time in the same direction? Am I correct in thinking the changing magnetic field induces an emf pointing into the page? Or generates what is considered back/counter- emf outside of the wire?
When I go to back solve for the strength of the electric field in the x, y, and z directions after generically taking the curl of the electric field's components and setting it equal to the negative of the partial derivative with respect to time of a circular magnetic field (arbitrarily made the magnetic field change linearly with time to make the math easier), I find myself with a differential equation that I sort of just simplified with assumptions that I don't think are valid. Assuming the E-fields X and Y components are zero ensures the cross product on the left hand side ∇ x E still remains a valid solution to the partial derivative -dB/dt on the right hand side of the equation. However this is sort of just what I'm hoping will happen and it's not exactly a valid method of solving differential equations last time I checked haha.
Anyone want to shed some light on how they've done this problem in the past? I guess I am unsure whether I am just missing some first principle physics or if the lack of Z component in the magnetic field allows some assumptions about the X and Y direction of the of the E-field to be formed. Or if I just have a lot of dif eq to do... :)
Thanks in advance for any help!
When I go to back solve for the strength of the electric field in the x, y, and z directions after generically taking the curl of the electric field's components and setting it equal to the negative of the partial derivative with respect to time of a circular magnetic field (arbitrarily made the magnetic field change linearly with time to make the math easier), I find myself with a differential equation that I sort of just simplified with assumptions that I don't think are valid. Assuming the E-fields X and Y components are zero ensures the cross product on the left hand side ∇ x E still remains a valid solution to the partial derivative -dB/dt on the right hand side of the equation. However this is sort of just what I'm hoping will happen and it's not exactly a valid method of solving differential equations last time I checked haha.
Anyone want to shed some light on how they've done this problem in the past? I guess I am unsure whether I am just missing some first principle physics or if the lack of Z component in the magnetic field allows some assumptions about the X and Y direction of the of the E-field to be formed. Or if I just have a lot of dif eq to do... :)
Thanks in advance for any help!