The coil a produces a magnetic field uoNla Its flux linking for each turn in the coil b ab=p0Na·丌B and its total flux linking in the coil b is ab=NbΦab=07B2N"Nbla The mutual inductance is TRNM wor- NaNb/la
12.2 Induced electromotance in Terms of mutual Inductance a change in Ia induces the electromotance in b ab This equation is convenient to calculate vh, since M and dIa/dt are easy to measure Note that we can write aA Db=fbE·d1=fb(-+)·dl, where a is the vector potential at b produced by la Similarly, a change in Ib induces the electromotance n a
Example: The Vector Potential of The Inner solenoid The inner solenoid produces b=0 ouside itself, but a change in la induces an electromotance in the outer solenoid b