The magnitude of the drift velocity per unit electric field is known as . . . . . . .

$A$ potential difference of $5 \,V$ is applied across a conductor of length $10 \,cm$. If the drift velocity of electrons is $2.5 \times 10^{-4} \,m/s$,then the electron mobility will be ............ $m^2 V^{-1} s^{-1}$.

Two cylindrical rods of uniform cross-sectional area $A$ and $2A$,having free electrons per unit volume $2n$ and $n$ respectively,are joined in series. $A$ current $I$ flows through them in a steady state. Then the ratio of the drift velocity of free electrons in the left rod to the drift velocity of electrons in the right rod is $\left( \frac{v_L}{v_R} \right)$.

$A$ metal wire is subjected to a constant potential difference. When the temperature of the metal wire increases,the drift velocity of the electron in it

The total momentum of electrons in a straight wire of copper of length $1\, m$ carrying a current of $16\, A$ is

$A$ copper wire of diameter $1.02\, mm$ carries a current of $1.7\, A$. Find the drift velocity $(v_d)$ of electrons in the wire. Given $n$,the number density of electrons in copper $= 8.5 \times 10^{28} /m^3$. (Express the answer in $mm/s$)