We know that the charge on an electron is negative and it is -1.6⨯10-19 coulomb.
We need to calculate the number of electrons constituting one coulomb of charge.
e =1.6 × 10^-19 C
Total charge required 1Coulomb.
Therefore q = 1C
We know the formula
Hence, 1 C charge is carried by
Substituting the values in equation (i) we get,
1/ (-1.6⨯10^-19) = 6.25 ⨯ 10^18 electrons.
So, if 1 A current flows through a conductor, then
6.25 ⨯ 10^18 electrons pass per a second across the cross-section of the conductor.