If 30 C of electric charge flows past a point in a wire in 2 minutes, what is the current in the wire?
Answer:
Charge, Q = 30C
Time taken for the charge flow, t = 2 minutes = 120s
(Since the unit of current, Ampere (A) is also equal to Coulomb per second (Cs-1), the unit of time must be changed to second)
Current, I = ?
\begin{gathered}
I = \frac{Q}
{t} \hfill \\
I = \frac{{30}}
{{120}} = 0.25A \hfill \\
\end{gathered}