Question

Define coefficient of mutual inductance of two cells. A secondary coil of n2 turns is wound on a long solenoid of area of cross section. A having a primary coil of n1 turns per unit lenght . what is the mutual inductance of two cells?

Answer 1

M = [(Uo N1 N2 i A)/ l] / i
M = Uo N1 N2 A / l
is the mutual inductance between two long Co axial solenoids