Question

Two coils are placed close to each other. The mutual inductance of the pair of coils depends upon

(a) the rates at which currents are changing in the two coils
(b) relative position and orientation of the two coils
(c) the materials of the wires of the coils
(d) the currents in the two coils.

Answer 1

(c)  Mutual inductance between two coils depends on the materials of the wires of the coils.