A current of 1 microampere is drawn by a device for three hours. Find the amount of electric charge that flows through the circuit.

Given: 
Current, I = 1 microampere = 1 x 10^-6 A
Time, t = 3 hours = 3 x 3600 = 10800 s

To find: 
Charge (Q )

Solution:
When there is a net movement of electric charge across space, an electric current is present. It is the flow of charge per unit of time.

$\mathrm{I}=\frac{\mathrm{Q}}{\mathrm{t}}$
$\therefore \mathrm{Q}= \mathrm{I}\times \mathrm{t}$
$=\left(1\times {10}^{-6}\right)\times \left(10800\right)$
$=\left(10800\times {10}^{-6}\right)$
$=0.0108 \mathrm{C}$

Therefore, the electric charge of 0.0108 C will flow through the circuit.