What Have I Learned So Far? 1. The core of a solenoid produces a magnetic flux of 6 x 10 wb. Meanwhile, removing the core produces a flux of 4 x 10' Wb in the solenoid with the same amount of current. Compute the relative permeability of the core. 2. A 75-cm long solenoid is wound with 5 500 turns on an aluminum rod with a radius of 0.77 cm. Compute the flux through the solenoid if a current of 4 A is supplied to it. The relative permeability of aluminum is 250. BIG IDEA Magnetic poles have associated magnetic forces. Around each magnetic pole is a