Question

how many electrons constitute an electric current of 2A

Answer 1

In 2 Ampere current, the amount of charge involved is 2 Coulombs.

2 coulombs of electric charge flows through a cross section of wire in one second.  Each electron carries a charge of -1.6 * 10⁻¹⁹ C approx.

2 C charge = 2 C /[1.6 * 10⁻¹⁹ C]   number of electrons.
                  = 1.25 * 10¹⁹ electrons.   
Answer...

Answer 2

your answer is 1.25×10^ -19 columb