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

The current flowing through a wire varies with time according to the formula $I = 3t^2 + 2t + 5$. The total charge passing through a cross-section of the wire in the interval from $t = 0$ to $t = 2$ seconds is ........... $C$.

An electron moves with a constant speed of $4 \times 10^6 \, m/s$ in a circle of radius $10 \, cm$. Find the electric current at any point on the circle.

$62.5 \times 10^{18}$ electrons per second are flowing through a wire of area of cross-section $0.1 \, m^2$. The value of the current flowing will be ............ $A$.

$A$ current of $5\,A$ flows through a resistance of $10\, \Omega$ for $4$ minutes. The total charge in Coulombs and the number of electrons passing through any cross-section of the resistor in this time are, respectively:

The electric current in a conductor varies with time $t$ as $I = 2t + 3t^2$,where $I$ is in amperes and $t$ is in seconds. Find the total charge $Q$ (in $C$) that passes through the cross-section of the conductor from $t = 2 \ s$ to $t = 3 \ s$.