# Even when the drift velocity of the electrons is very small, how is current in the circuit established immediately?

So I have this question in my textbook and Ive also got it in my test. Ive written a wrong answer. My friend wrote the drift velocities of each particle add up and he got full marks. Is it right? Can you please explain. I have checked this answer elsewhere but they use terms such electromagnetic waves which is not yet thought to us. Could you please explain in simple terms? Ok, this is the edited question. This was the answer of my teacher: $I=neAv_d$. Although $v_d$ is very small but $n$ the number density of electrons is very very large as compared to the drift velocity hence although the velocity of the electrons is very small to get to the other end instantly but they are so large in number that the current is established immediately. Is this the right definition?

• Each electron pushes the next one! – lucas Jun 24 '16 at 13:47