Relation between conductivity (σ) and current density (J)

 


1) We know Conductivity


2) Current density  




3) from ohm’s law   V = IR

 


 4) again

 


5) then

 V = IR

 



 

Now putting the value of conductivity

 


And for current density





6) Again suppose E is the electric field applied to the conductor of length l  then

V = E l

 


7) therefore we have