Inductance of solenoid ' L ' having diameter ' d '. Let n be the number of turns per unit length. The inductance per length near the middle of a solenoid is (Asume that current passes through the turns, ₀= Permeability of vacuum)

Step-by-step solution

Concept: Using the definition of the flux associated through the surface we can obtain the inductance per unit length near the center of the solenoid. We define selfinductance L as: = Li where, is the associated flux and i is the current through the solenoid. = B A where, B= ( ₀ . in ), A=2 d^2 4 is the area. aligned & Li = ( ₀ in ) ( n d ^2 4 ) & L = ₀ n ^2 ~d ^2 4 aligned