Is electric current a scalar? Can it be negative?

Question

.sam. · Answer

THAT is what I thought also

unklerhaukus · Answer

i got it wrong,

i dont really understand why

.sam. · Answer

Aw

dls · Answer

Current is scalar and it cannot be negative.

dls · Answer

$$\LARGE I= - \frac{dQ}{dt}$$
indicates that flow of current per unit time is decreasing maybe the question posted is a subpart of another question or perhaps incomplete.

dls · Answer

@yrelhan4 ? :O

yrelhan4 · Answer

the convention that we follow is movement of -ve charge as current right?

anonymous · Answer

@DLS  current can be negative

anonymous · Answer

normally we don't take current as a vector and instead use the length vector instead.

anonymous · Answer

because its scalar

ganeshie8 · Answer

|dw:1367418867689:dw|

ganeshie8 · Answer

if i assume that way is +ve, then the reverse of it will be -ve. in a circuit we assume current directions initially. based on that we get -ve or +ve numbers after analysis

anonymous · Answer

becoz current does'nt follow vector algebra so, it is scalar.

agent0smith · Answer

"the convention that we follow is movement of -ve charge as current right?" 

I think this is why. Current is created by flow of electrons which go from - to +, but current is defined as + to -.

agent0smith · Answer

Still, this site uses no negative sign, it has your answer... http://physics.tutorvista.com/electricity-and-magnetism/electric-current.html

unklerhaukus · Answer

maybe electric current is a phasor

agent0smith · Answer

Hmm, i guess current can be negative, because it does have direction (it can come up like that when using Kirchoff's laws, to find current in loops of a circuit).

yrelhan4 · Answer

http://openstudy.com/study#/updates/4fb98da9e4b05565342e8394 Look what phoneix_rags and chrsimmo have said.. hmm.. scalar i'd say now..

yrelhan4 · Answer

and why it is not a vector even though it has direction... i'll give it to ruchi..
still not 100% sure about what current is.. but scalar looks good to me.

yrelhan4 · Answer

ok another example.. for force on a current carrying wire in a magnetic field
F=IdL×B .. here B is a vector.. and dL is a vector.  we take the the direction of current to decide the direction of dL.. and it completely depends on what coordinate system we choose.