$A$ metallic block has no potential difference applied across it. What is the mean velocity of free electrons in terms of $T$ (absolute temperature of the block)?

$A$ constant electric current $I$ is passed through a straight conductor of length $l$. If $S$ is the specific charge of an electron,then the total momentum of the electrons is:

$A$ current of $5 \,A$ is passing through a metallic wire of cross-sectional area $4 \times 10^{-6} \,m^{2}$. If the density of charge carriers of the wire is $5 \times 10^{26} \,m^{-3}$, the drift velocity of the electrons will be:

For a cylinder of radius $R$,the current density is given by $J = J_0 \frac{r}{R}$,where $J_0$ is a constant and $r$ is the distance from the axis. Calculate the total current.

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

An insulating pipe of cross-section area $A$ contains an electrolyte which has two types of ions with charges $-e$ and $+2e$. $A$ potential difference applied between the ends of the pipe results in the drifting of the two types of ions,having drift speeds $v$ (for $-e$ ion) and $v/4$ (for $+2e$ ion). Both ions have the same number density $n$. The current flowing through the pipe is: