Question 315: Current Electricity

Question

A copper rod of cross-sectional area A carries a uniform current I through it. At temperature T, if the volume charge density of the rod is $$\rho $$,  how long will the changes take to travel a distance d ?

Accepted Answer

Given : Volume charge density of rod = $$ho$$.
We know that current $$I = neA{v_d}$$; where n is number of electrons, e is electronic charge, A is area, v
d
is drift velocity
Since volume charge density is $$ho$$ = ne. Therefore,
$$I = ho A{v_d} \Rightarrow {v_d} = {I \over {{ho _A}}}$$
Now, time = $${{dis	an ce} \over {speed}}$$
$$\Rightarrow$$ time $$ = {d \over {{v_d}}} = {d \over {I/ho A}} = {{ho Ad} \over I}$$
Thus, time required to travel distance $$d = {{ho dA} \over I}$$

Answer

$${{2\rho \,d\,A} \over {\rm I}}$$

Answer

$${{2\rho \,d\,A} \over {{\rm I}\,T}}$$

Answer

$${{\rho \,d\,A} \over {{\rm I}\,}}$$

Answer

$${{\rho \,d\,A} \over {{\rm I}\,T}}$$

Current Electricity

A copper rod of cross-sectional area A carries a uniform current I through it. At temperature T, if the volume charge density of the rod is $\rho $, how long will the changes take to travel a distance d ?

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