

Electric
Current (Scalar Quantity) 

(I) Electric current I = q/t.
As both charge and time are scalars, therefore electric current
is a scalar quantity.




(II)
We show electric current in a wire by an arrow to indicate
the direction of flow of positive charge. But such arrows
are not vectors because they do not obey the laws of vector
algebra. This point can be explained y referring to fig. The
wire OA and OB carry currents of 3A and 4A respectively. The
total current in the wire CO is 3 + 4 = 7A irrespective of
the angle between the wires OA and OB. This is not surprising
because the charge is conserved so that magnitudes of current
in wires OA and OB must add to give the magnitude of current
in wire CO. 
