A typical commercial speaker has an impedance of 8Ω. If this impedance is mostly provided by its inductance, the inductance is about 3 × 10−4H. Nathan, Kelly, and Josh wanted to use an entire spool of wire to make their speaker in lab. The coil was about 5cm long, had a radius of about 3cm and contained 1000 turns of wire. Calculate the inductance of the coil of wire approximating it as an infinite solenoid.

(a) L = 0.0036H. (b) L = 0.071H. (c) L = 0.33H. (d) L = 2.4H. (e) L = 4.7H