Assuming we have a 1 cm long empty solenoid with a 1 mA current flowing through it, how many loops do we need to have in the solenoid to generate a 1 T magnetic field inside the solenoid? Give your answers as integers rounded up N = What if we had an iron core inside the solenoid with relative permeability of 64,000 ? How many loops would we need in this case? N =