$A$ uniform copper wire carries a current $i$ amperes and has $p$ carriers per meter$^3$. The length of the wire is $\lambda$ meters and its cross-section area is $s$ meter$^2$. If the charge on a carrier is $q$ coulombs,the drift velocity in $ms^{-1}$ is given by

The drift velocity of electrons for a conductor connected in an electrical circuit is $V_{d}$. The conductor is now replaced by another conductor of the same material and same length but with double the area of cross-section. The applied voltage remains the same. The new drift velocity of electrons will be

There is a current of $40 \ A$ in a wire of cross-sectional area $10^{-6} \ m^2$. If the number of free electrons per $m^3$ is $10^{29}$,then the drift velocity will be:

Derive the equation of mobility in terms of electric current.

$A$ silicon block at $300\,K$ has a length of $10\,cm$ and a cross-sectional area of $1 \times 10^{-4}\,m^2$. If a $2\,V$ battery is connected across its ends parallel to the length,find the current flowing through it. The electron mobility is $0.14\,m^2V^{-1}s^{-1}$ and the electron number density is $1.5 \times 10^{16}\,m^{-3}$.

The unit of mobility in terms of fundamental units is . . . . . . .