Question

Define the term mutual inductance between the two coils. Obtain the expression for mutual inductance of a pair of long coaxial solenoids each of length l and radii `r_(1)andr_(2)(r_(2)gtgtr_(1))`. Total number of turns in the two solenoids are `N_(1)andN_(2)` respectively.

Answer 1

The mutual inductance of two long coaxial solenoids,
`M_(12)=M_(21)=(mu_(0)N_(1)N_(2)A_(1))/(l)=(mu_(0)N_(1)N_(2)(pir_(1)^(2)))/(l)[becauser_(1)ltltr_(2)]`