(a) A loop of wire carries a conventional current of $0.8 \mathrm{A}$. The radius of the loop is $0.09 \mathrm{m}$. Calculate the magnitude of the magnetic field at a distance of $0.32 \mathrm{m}$ from the center of the loop, along the axis of the loop. (b) What would be the magnitude of the magnetic field at the same location if there were 100 loops of wire in a coil instead of one loop?