Solution

(c)6.25x 10⁻¹⁸

We know that the charge on an electron is negative and it is -1.6x 10-19 coulomb. We need to calculate the number of electrons constituting one coulomb of charge. e=1.6 x 10⁻¹⁹ C Total charge required 1Coulomb. Therefore q=1C We know the formula q=ne n = q/e------ (i) Hence, 1C charge is carried by Substituting the values in equation (i) we get, 1/(-1.6x10⁻¹⁹) = 6.25 x 10⁻¹⁸ electrons. So, if 1 A current flows through a conductor, then 6.25 x 10⁻¹⁸ electrons pass per a second across the cross-section of the conductor.