The electric intensity $E$,current density $j$,and specific resistance $\rho$ (often denoted as $k$ in some texts) are related to each other by the relation:

There is a current of $1.344 \, A$ in a copper wire whose area of cross-section normal to the length of the wire is $1 \, mm^2$. If the number of free electrons per $cm^3$ is $8.4 \times 10^{22}$, then the drift velocity would be

Every atom contributes one free electron in copper. If $1.1 \ A$ current is flowing in a copper wire having a $1 \ mm$ diameter,then the drift velocity (approx.) will be (Density of copper $= 9 \times 10^3 \ kg \ m^{-3}$ and atomic weight $= 63$).

$A$ current of $2 \,A$ is passing through a metal wire of cross-sectional area $2 \times 10^{-6} \,m^{2}$. If the number density of free electrons in the wire is $5 \times 10^{26} \,m^{-3}$, the drift speed of electrons is (Given, $e = 1.6 \times 10^{-19} \,C$)

The relationship between the electric field $E$ and the current density $J$ is given by:

What is current density? Derive Ohm's law in the form of current density.