The potential difference across a conducting wire of length $20 \ cm$ is $30 \ V$. If the electron mobility is $2 \times 10^{-6} \ m^2 \ V^{-1} \ s^{-1}$,then the drift velocity of the electrons is

The dimensional formula of mobility is . . . . . .

In a copper wire,each atom releases one free electron. If the diameter is $1\, mm$ and the current is $1.1\, A$,find the drift velocity. (Given: Density $\rho = 9 \times 10^{3}\, kg/m^3$,Molar mass $M = 63\, g/mol$,Avogadro number $N_A = 6.023 \times 10^{23}\, mol^{-1}$,Elementary charge $e = 1.6 \times 10^{-19}\, C$)

The drift velocity of free electrons in a conductor is $v$ when a current $i$ is flowing in it. If both the radius and current are doubled,then the drift velocity will be

An electric cell of emf $E$ is connected across a copper wire of diameter $d$ and length $l$. The drift velocity of electrons in the wire is $v_{d}$. If the length of the wire is changed to $2l$,the new drift velocity of electrons in the copper wire will be

$A$ straight conductor of uniform area of cross-section carries a current $I$. If $s$ is the specific charge (charge-to-mass ratio) of the electron,what is the total momentum of all the electrons per unit length of the conductor due to their drift velocity?