Induction, Coefficient of Mutual

The coefficient of mutual induction of two circuits is the quantity of magnetic induction pa ing through either of them per unit current in the other. (Emtage.) It is also defined as the work which must be done on either circuit, against the action of unit current in each, to take it away from its given position to an infinite distance from the other; and also as the work which would be done by either circuit on the other in consequence of unit current in each, as the other moves from an infinite distance to its given position with respect to the other conductor. It depends on the form, size, and relative position of the two circuits; and on the magnetic susceptibilities of neighboring substances. The ether surrounding two circuits of intensity i' and i" must po e energy, expre ible (Maxwell) as 1/2 L i2 + M i i + 1/2 N i12. It can be shown that M i i1 in any given position of the two circuits is numerically equal (1) to the mutual potential energy of the two circuits (2) to the number of lines of induction, which being due to A, pa from A through B, or equally being due to B, pa from B through A, and M is styled the coefficient of mutual induction. (Daniell.) 302   STANDARD ELECTRICAL DICTIONARY.