Question

How many electrons pass through a conductor in 3 milliseconds if the current is 5 mA

Answer 1

Charge passed through a conductor:

$q=It=5\cdot10^{-6}\cdot3\cdot10^{-3}=1.5\cdot10^{-10}C$

E:lementary charge:

$e=1.6\cdot10^{-19}C$

Number of electrons pass through a conductor:

$n=q/e=\frac{1.5\cdot10^{-10}}{1.6\cdot10^{-19}}=9.375\cdot10^{8}$