  Dynamic processes occurring in solar active regions are dominated by the
solar magnetic field. As of now, observations using a solar magnetograph have
supplied us with the vector components of a solar photospheric magnetic field.
The two transverse components of a photospheric magnetic field allow us to
compute the amount of electric current. We found that the electric current in
areas with positive (negative) polarity due to the longitudinal magnetic field
have both positive and negative signs in an active region, however, the net
current is found to be an order-of-magnitude less than the mean absolute
magnitude and has a preferred sign. In particular, we have statistically found
that there is a systematic net electric current from areas with negative
(positive) polarity to areas with positive (negative) polarity in solar active
regions in the northern (southern) hemisphere, but during the solar minimum
this tendency is reversed over time at some latitudes. The result indicates
that there is weak net electric current in areas of solar active regions with
opposite polarity, thus providing further details about the hemispheric
helicity rule found in a series of previous studies.
