MLA Citation: Bloomfield, Louis A. "Question 896"How Everything Works 17 Jul 2018. 17 Jul 2018 .
896. You have mentioned the relationships between electric fields, magnetic fields, and current. Which causes which? Does current cause a magnetic field, in turn, causing flow in the next circuit and so forth? What is this order of occurrence? — BJ
Those three items, electric fields, magnetic fields, and currents, are strongly interrelated. Here are some of those relationships: (1) currents cause magnetic fields, (2) currents that change with time cause magnetic fields that change with time, (3) magnetic fields that change with time cause electric fields, (4) electric fields cause currents to flow in electric conductors. From these relationships, you can see that any time you have a changing current through one circuit, you can end up with a current flowing through another nearby circuit. Power moves from the first circuit to the second circuit with the help of a magnetic field and an electric field. A moving magnet also produces a magnetic field that changes with time and it can send a current through a nearby circuit, too.