The relation between the current $i$ (in ampere) in a conductor and the time $t$ (in second) is $i=12 t+9 t^2$. The charge passing through the conductor between the times $t=2 \,s$ and $t=10 \,s$ is (in $C$)

$5 \, A$ of current is passed through a metallic conductor. The charge flowing in one minute in coulombs will be:

Write the direction of the electric current between the electrodes of an electric cell.

$A$ 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 ............... $C$.

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 $C$)

Define electric current and explain it. Write its $SI$ unit.