Question

How is current density a vector?

Answer 1

Woah I haven't gotten that far in the chapter yet.In the beggining itself while stating it they said current density is a vector and current is not

Answer 2

oh i tink he only wants to know why it has magnitude and direction.

Answer 3

I can see it has magnitude of current per unit area.But Im thinkin if current is not a vector how is current density a vector?

Answer 4

Well,there is is in that direction too.If current is not a vector how is current density a vector?

Answer 5

I meant current is in that direction too

Answer 6

the current is just flow of charge ... it follows the electric field.

Answer 7

And how is current density any different.It is current per unit area right?

Answer 8

Electric current density J is simply the electric current per unit area. Its magnitude can be written as a ratio of an infinitesimal current dI (SI unit: A)to an infinitesimal area dA (SI unit: m2): [3]




In vector form, the direction of J is in the direction the charge carriers move, though since the definition includes area, the relative directions between the vector area A and current density vector J also affect the magnitude:


straight from wiki

Answer 9

But why is it in vector form in the first place?

Answer 10

I was thinking on these lines.See if I am right please

Answer 11

The charge carriers collide with the ions and stuff and when you apply a electric field in the conductor they acquire a drift velocity towards the electric field.So they slowly move along with the electric field as a whole.But if taken minutely which is current density then each one is basically in a different direction?