Two coils are placed close to each other. The mutual inductance of the pair of coils depends upon
The currents in the two coils
The rates at which currents are changing in the two coils
Relative position and orientation of the two coils
The materials of the wires of the coils
Mutual induction depends on
i) material of the core
ii) no. of turns
iii) relative position and orientation of coils
iv) coupling