### Theory:

Electric current is a flow of electirc charges, in a particular direction.
Ampere is the SI unit of Electric current and it is denoted as '$$A$$'.
• Сoulomb ($$C$$) is the unit of electric charge.
• Ampere is a unit of electric current equal to a flow of one coulomb per second.
• The coulomb is defined as the quantity of electricity transported in one second by a current of one ampere.
• 'One ampere' is defined as one 'coulomb' of charge moving in a conductor in one second.
Ammeter is the device used to measure the electric current.

For example: When $$3$$ coulombs of charge flow through a circuit for $$15$$ seconds, calculate the current.

Given: Charge $$Q = 3\ C$$; time $$t = 15\ s$$

$\begin{array}{l}\mathit{Electric}\phantom{\rule{0.147em}{0ex}}\mathit{current}\phantom{\rule{0.147em}{0ex}}\left(I\right)\phantom{\rule{0.147em}{0ex}}=\frac{\phantom{\rule{0.147em}{0ex}}\mathit{Amount}\phantom{\rule{0.147em}{0ex}}\mathit{of}\phantom{\rule{0.147em}{0ex}}\mathit{electric}\phantom{\rule{0.147em}{0ex}}\mathit{charges}\phantom{\rule{0.147em}{0ex}}\mathit{flowing}\phantom{\rule{0.147em}{0ex}}\mathit{through}\phantom{\rule{0.147em}{0ex}}a\phantom{\rule{0.147em}{0ex}}\mathit{conductor}\phantom{\rule{0.147em}{0ex}}\left(Q\right)\phantom{\rule{0.147em}{0ex}}}{\mathit{Time}\phantom{\rule{0.147em}{0ex}}\left(t\right)}\phantom{\rule{0.147em}{0ex}}\\ I=\frac{Q}{t}\\ \\ I=\frac{3}{15}\phantom{\rule{0.147em}{0ex}}\\ \\ I\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}0.2\phantom{\rule{0.147em}{0ex}}A\phantom{\rule{0.147em}{0ex}}\end{array}$