A toroidal solenoid with \(N\) tightly wound turns carries a constant current \(I\). The toroid has an inner radius \(a\) and an outer radius \(b = 2a\). What is the ratio \(B_{\text{inner}} / B_{\text{outer}}\) of the magnetic field magnitude at the inner radius \(r = a\) to the magnetic field magnitude at the outer radius \(r = 2a\) inside the toroid?