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

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b. b. at twice the distance, the magnitude of the field is 2b. c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.