- #1

- 784

- 11

I = (Q/t) =

(nVq)/t

where n is the number of charges, V is the volume, q is the average charge and t is time.

nVq/t = n(Ax)q/t = nAvq

where v is velocity.

Current Density = (I/A)

(nAvq)/A = nvq

My question is on the step where it goes Q/t = nVq/t

Why does Q (total charge) not just equal nq? Why is there a volume term thrown in there?