What is the order of current flowing in the nerves of our body?

An electron (charge $= 1.6 \times 10^{-19} \text{ C}$) is moving in a circle of radius $5.1 \times 10^{-11} \text{ m}$ at a frequency of $6.8 \times 10^{15} \text{ rev/s}$. The equivalent current is approximately:

In a conductor,$4$ coulombs of charge flows for $2$ seconds. The value of electric current will be:

$A$ steady current is flowing in a metallic conductor of non-uniform cross-section. The physical quantity which remains constant is

The current flowing through a wire depends on time as $I = 3t^2 + 2t + 5$. The charge flowing through the cross-section of the wire in the time interval from $t = 0$ to $t = 2 \ s$ is: (in $C$)

$A$ current $I = I_{0} e^{-\lambda t}$ is flowing in a circuit. The total charge that flows through the circuit over the entire pulse period (from $t = 0$ to $t = \infty$) is: