A steady current flows in a metallic conductor of non-uniform cross-section i.e., `i` : constant. `A ne` constant.
A. `j = (i)/(A), j` vary with area of `X-section`
B. `j = sigma E`,
`(i)/(A) = sigma E rArr (i)/(sigma A) = E` `E` : changes with `A`
C. `j = n e v _d`
`(i)/(A) = n e v_d`
`v_d = (i)/(n e A), v_d` varies with `A`
D. All options are correct
