I = d Q d t {\displaystyle I={\frac {dQ}{dt}}}
I = n e A v d {\displaystyle I=neAv_{d}\,}
J = I A {\displaystyle J={\frac {I}{A}}}
J = n e v d {\displaystyle J=nev_{d}\,}
ρ = E J {\displaystyle \rho ={\frac {E}{J}}}
Q = N e = n e A L {\displaystyle Q=Ne=neAL\,}
R = ρ L A {\displaystyle R={\frac {\rho L}{A}}}
