$A$ 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, $e = 1.6 \times 10^{-19} \,C$)

When a potential difference is applied across a linear metallic conductor,then:

An ionization chamber with parallel conducting plates as anode and cathode has $5 \times 10^7$ electrons and the same number of singly-charged positive ions per $cm^3$. The electrons are moving at $0.4\, m/s$. The current density from anode to cathode is $4\,\mu A/m^2$. The velocity of positive ions moving towards cathode is ............. $m/s$. [$AIPMT$ $1992$]

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

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 $\left( \frac{v_L}{v_R} \right)$.

Why is the average velocity of an electron at time $t$ equal to zero in the absence of an external electric field?