The mechanism of the heat produced in a conductor when an electric current flows through it can be explained on the basis of

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:

Which particles are responsible for the conductivity of metals?

$A$ wire of diameter $0.02\,m$ contains $10^{28}$ free electrons per cubic meter. For an electrical current of $100\,A$,the drift velocity of the free electrons in the wire is nearly:

$A$ current of $1.6\, A$ is flowing through a wire having a cross-sectional area of $1\, mm^2$. If the density of free electrons in the material of the wire is $10^{29}\, m^{-3}$,the drift velocity of the electrons will be:

Assertion: Free electrons always keep on moving in a conductor,even then no magnetic force acts on them in a magnetic field unless a current is passed through it.
Reason: The average velocity of free electrons is zero.