10)
Current per unit area (taken normal to the current), I/A, is called
current density and is denoted by j The SI units of the current density
are A/m2 Further, if E is the magnitude of uniform electric field in the
conductor whose length is l, then the potential difference V across its
ends is El Using these, the last equation reads
GEORG SIMON OHM (1787–1854)
Georg Simon Ohm  (1787–
1854) German physicist,
professor at Munich