Define the $SI$ unit of electric charge in terms of the Ampere.

(N/A) The $SI$ unit of electric charge is the Coulomb $(C)$.
By definition,the current $I$ is the rate of flow of charge $Q$ through a cross-section of a conductor,given by $I = Q/t$.
Therefore,$Q = I \times t$.
When a steady current of $1 \; A$ flows through a conductor for a time interval of $1 \; s$,the quantity of charge that passes through its cross-section is defined as $1 \; C$.
Thus,$1 \; C = 1 \; A \times 1 \; s$.