Two solenoids of equal length and almost equal cross-sectional area are fully inserted into one another Find their mutual inductances are equal to `L_(1)` and `L_(2)`.

A tightly wound solenoid of length l and cross sectional area A_(1) is partly inserted co-axially into another tightly wound solenoid of length l and cross section A_(2) (gt A_(1)) . The centres of the two solenoids are separated by x (lt l) . Assume that A_(2) lt lt x^(2), A_(2) lt lt l^(2) . Calculate the total magnetic field energy inside the solenoid when both of them carry same current (I) in the same sense. Number of turns in each solenoid is N.

Mutual inductance of two coils depends on their self inductance L_(1) and L_(2) as :

Mutual inductance of two coils depends on their self inductance L_(1) and L_(2) as :

The number of turns of a solenoid of length l and area of cross-section A is N. The self-inductance L increases as

The self inductance of a solenoid of length L, area of cross-section A and having N turns is-

The self inductance of a solenoid of length L, area of cross-section A and having N turns is-