Why isn't current a vector despite having both magnitude and direction?

Question

jamesj · Answer

We can think of all real number quantities as 1-dimensional vectors.  E.g., energy, height relative to my dining room table.

But there's not much to be added by doing so.  Hence those quantities together with current we just think of as real numbers.

anonymous · Answer

@James: So the direction of current is insignificant?

anonymous · Answer

Also most of time direction information is in L

$$I L x  B$$

jamesj · Answer

Is +5 J different from -5 J ?  Yes.

Hence the direction is important, but it's usually just a question of sign: it flows this way around the circuit, or the opposite direction.

None the less, there are some cases, when we really do want to think of it as a vector in 3-d space.

But most of the time, it's sufficient to think of it as a scalar quantity.

anonymous · Answer

$$I \overrightarrow{L} \times \overrightarrow{B}$$

anonymous · Answer

If I say, we cannot apply the vector laws of addition like the parallelogram law in adding two currents and so it is a scalar, would my assumption be right?

anonymous · Answer

we do have to take direction in account; for example when doing K C L

jamesj · Answer

If current is a vector, then all all vector properties apply.  

For example, in the equation for the Lorentz force the imran91 has written down.

jamesj · Answer

E.g., see here: http://en.wikipedia.org/wiki/Lorentz_force#Force_on_a_current-carrying_wire

anonymous · Answer

What is the purpose of mentioning the Lorentz force in this question??

jamesj · Answer

The equation for the Lorentz force is a good example where it is essential to think of current as a vector quantity.  

You'll notice however that in at least one formulation the current $ I $ remains a scalar and the direction is given to the wire as $ L $.

anonymous · Answer

ah! I got it....actually more than I wanted....thanks to each of your for your explanation.