On what factor does the mutual inductance depend between two coils.

The correct option is D

All of these

Explanation for the correct answer:

In case of option D:

Mutual Inductance:

1. Magnetic flux is induced by a changing current in one coil across a nearby coil. as a result, an emf is generated in adjacent coils.
2. Mutual inductance refers to the interaction of one coil's magnetic field with that of another coil.
3. Mathematically, Mutual inductance $L=\frac{N^2\mu A}{l}$, Where $N,\mu ,A,l$ are number of turns, the permeability of core material, the area of the wire, and average length respectively.
4. Hence, as evident from the above relation, Mutual inductance depends upon all the factors listed in options A, B, and C.
5. Thus, option D is the correct option.

Explanation for the incorrect answers:

1. There are no incorrect options.
2. In case of options A, B and C:
3. As seen from the formula for mutual inductance between two coils above.
4. We can conclude that mutual inductance depends upon the Cross-sectional area of the common core, The number of their turns, and the Permeability of the core.
5. Thus all the above-listed options are correct.

Thus, the correct option is option D.