The charge on a capacitor plate in a circuit,as a function of time,is shown in the figure. What is the value of current at $t = 4 \, s$ ? ............... $\mu A$

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

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 $t = 3 \ s$.

$62.5 \times 10^{18}$ 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 ............ $A$.

In an electrolyte,$3.2 \times 10^{18}$ bivalent positive ions drift to the right per second,while $3.6 \times 10^{18}$ monovalent negative ions drift to the left per second. Then the current is:

$A$ current of $1\, mA$ is flowing through a copper wire. How many electrons will pass a given point in one second?