Dependence of Mutual Inductance #8211; (i) Number of turns (N<sub>1</sub>, N<sub>2</sub>) of both coils, (ii) Coefficient of self-inductances (L<sub>1</sub>, L<sub>2</sub>) of both the coils, (iii) Area of cross-section of coils, (iv) Magnetic permeability of medium between the coils (μ<sub>r</sub>) or nature of material on which two coils are wound, (v) Coupling factor K between primary and secondary coils, (vi) Distance between two coils (As, d ↑ = M ↓), (vii) Orientation between primary and secondary coil (for 90° orientation, no flux relation i.e. M = 0)