A parallel-plate capacitor has circular plates of radius \(R=15 \mathrm{~cm}\) and plate separation distance \(d=1 \mathrm{~mm}\). While it is charging, the potential difference across the plates is given by \(V(t)=V_{0}\left(1-e^{-t / \tau}\right)\) where \(V_{0}=12 \mathrm{~V}\) and \(\tau=4.0 \mathrm{~ms}\). What is the magnitude of the magnetic field between the plates at a distance \(r=5 \mathrm{~cm}\) from the axis of the capacitor at \(t=2 \mathrm{~ms}\) ?