題組內容

7. Consider a uniformly wound solenoid having \( N \) turns and length \( \ell \). Assume \( \ell \) is much longer than the radius of the windings and the core of the solenoid is air. (10%)

(A) What is the inductance \( (L) \) of the solenoid? (The permeability in free space is \( \mu_0 \))