Application Aromatic ring current has a huge effect on NMR (Nuclear Magnetic Resonance) spectroscopy This is a very sophisticated and modern way of identifying organic chemical compounds by using magnetic pulses to find a compounds physical and chemical properties. Specifically its hydrogen (proton) and carbon properties.  Since aromatic rings have a current and therefore a magnetic field they act differently when hit with a magnetic pulse than non aromatic organic compounds. The magnetic field induced by the ring current causes the electrons of the hydrogen's on the outside to deshield and the result is that the hydrogen show up farther down field in an NMR spectrum. This allows chemists to easily identify aromatic structures based on the NMR spectrum.  http://orgchem.colorado.edu/Spectroscopy/specttutor/imagesarom/tol.gif This is an HNMR spectrum of toluene, which is an aromatic compound. The peak on the left with a 5 above it represents the 5 hydrogen that are attached to the aromatic ring. They are so far down field because of the induced magnetic field due to the current compared to the three hydrogen attached to the methyl group.