Question

How does the current density in a conductor varies with the increase in temperature and length?

Answer 1

Answer:

Explanation:

If potential difference V is applied across a conductor of length 'l' and area of cross-section 'A' having number of free electrons per unit volume n. ... (a) current density increases with increase in potential gradient . (b) when temperature increases, relaxation time (τ) decreases and current density decreases.

Answer 2

Answer:As temp. increases the value of J decrease & with increase in length value decrease

Explanation:The eq. for J(current density) has been attached above from the eq. as l - length is inversely proportional to J.In the case of temp. ,as temp. increase the relaxation time decreases which decreases J.