Question

During a 72-ms interval, a change in the current in a primary coil occurs. This change leads to the appearance of a 6.1-mA current in a nearby secondary coil. The secondary coil is part of a circuit in which the resistance is 12 Ω. The mutual inductance between the two coils is 3.2 mH. What is the change in the primary current?

Answer 1

Let the change in primary current is  .

Current in secondary coil I_s=6.0 mA=6.010^-3 A.

Resistance in secondary coil R_s=12 .

Interval of time =72 ms=7210^-3 s.

Mutual inductance M=3.2 mH=3.210^-3 H.

Induced emf in secondary coil

We also know  

  

  

  Change in the primary current is 1.62 A.