Question:
Hi. I was wondering about inductance. Is inductance always
a constant? I ask because it seems like the changing magnetic flux
through the inductor creates a changing electric field, which in
turn changes the magnetic flux. This would produce non-constant
inductances, right?
Replies:
Andrew,
It actually depends on how the magnetic flux changes. If it changes at
a constant rate, perhaps steadily increasing, then the produced electric
field would be constant. Most magnetic flux does not change steadily.
Most of it is oscillating. This does in turn create an oscillating
electric field, which in turn creates an oscillating magnetic field, and
so on. You will end up with electric and magnetic flux patterns that
complement each other. They will reach a balance. Based on Maxwell's
Equations, it is even possible to have non-zero sinusoidal electric and
magnetic fields traveling through space without having any electric
charge or current present. This is called light.
Dr. Ken Mellendorf
Physics Instructor
Illinois Central College
NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.