Due to what is current formed in an electrolyte?

Explain the current formed in solid conductors in the presence of an external electric field.

Which of the following is a scalar quantity?

$A$ copper rod of cross-sectional area $A$ carries a uniform current $I$ through it. At temperature $T$,if the volume charge density of the rod is $\rho$,how long will the charges take to travel a distance $d$?

The current through a wire depends on time as $i = (2+3t)\, mA$. The charge crossing through a section of the wire in $1\, min$ is .............. $C$.

Given a current-carrying wire of non-uniform cross-section,which of the following is constant throughout the length of the wire?