The current intensity is defined as the amount of charge Q that passes through a certain point of an electrical wire in a time interval of [tex]\Delta t[/tex]:
[tex]I= \frac{Q}{\Delta t} [/tex]
In our problem, the current intensity is
[tex]I=12.0 mA=0.012 A[/tex]
while the amount of charge that passes a certain point of the wire is
[tex]Q=6.50 C[/tex]
If we re-arrange the previous equation:
[tex]\Delta t= \frac{Q}{I} [/tex]
we can find the time needed for this amount of charge to pass through a point of the wire:
[tex]\Delta t= \frac{6.50 C}{0.012 A} =541.7 s[/tex]
