(Edit, Question was previously: "Can a changing electric field produce a magnetic field?")
I've just began studying Maxwell's equations today and what really had my attention is Ampere's law, the second term in particular.
$$\int\vec B \cdot d\vec l=μ_0I_{encl}+μ_0ε_0\frac{dΦ_E}{dt}$$
Does this mean that a changing electric field can cause a magnetic field?
For example, during the charging of a capacitor, between the plates where the electric field is changing.
I saw an exercise example where we changed the voltage across a capacitor and thus created a magnetic field.But some websites state that as long as there is no current – charge movement , there is no magnetic field being created. I read the same about the capacitor in particular. Could the example be wrong or is there a difference ?
Best Answer
This is incorrect. Light propagation happens because a changing electric field can produce a magnetic field just like a changing magnetic field produces an electric field. Your initial conclusion is correct: a changing electric field is as much a source of magnetic field as current is.
So yes, there is a magnetic field in a capacitor while it is being charged. Once the charging is complete and the electric field becomes constant, it vanishes.