Question

A 12 mA steady current is flowing on a copper wire at a time interval of one

minute. Calculate the number of electrons passing on the copper wire

Answer 1

The net charge passing through the copper wire

$$q=It\\ =12*10^{-3}*60=0.72\:\rm C$$

The corresponding number of electrons

$$N=\frac{q}{e}=\frac{0.72}{1.6*10^{-19}}=4.5*10^{18}$$