$A$ steady current flows in a metallic conductor of non-uniform cross-section. Which of the following quantities is constant along the conductor?

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

The electric current through a wire varies with time as $I = I_0 + \beta t$,where $I_0 = 20 \ A$ and $\beta = 3 \ A/s$. The amount of electric charge that crosses through a section of the wire in $20 \ s$ is: (in $C$)

In conductors,in the absence of an electric field,although electrons are in motion,why is no current formed?

$A$ source of $e.m.f.$ $E = 15\,V$ and having negligible internal resistance is connected to a variable resistance so that the current in the circuit increases with time as $i = 1.2t + 3$. Then,the total charge that will flow in the first five seconds will be ............... $C$.

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