mutual inductance

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The principle that a change of current in one circuit can induce electromotive force in a neighboring circuit, equal to the ratio of the electromotive force in a circuit to the corresponding change of current in a neighboring circuit.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun physics the ratio of the voltage in a circuit to the change in current in a neighboring circuit

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a measure of the induction between two circuits; the ratio of the electromotive force in a circuit to the corresponding change of current in a neighboring circuit; usually measured in henries