Can current be negative?
Can current be negative? As from question you thought that its wrong, but no friend question is right but current is never negative but its calculation at end its as negative, let’s understand in details.
In this figure, several connecting elements are provided by conducting the wires, indicating the direction and the current flow. I have to find the current between elements I1 to I4. When applying Kirchoff’s Current Law to node A (indicated by the red arrow), receive: current input node = current node 0 = I2 + 7A + 3A I2 = -10A Similarly when applying law to node B blue arrow ) receive: current input node = current node 2A = I4 + 4A I4 = -2A Did I do something wrong or is it possible that the current has a negative value according to the direction? In other words, can the current be a vector quantity?
Currents flow from the positive end to the negative of a battery or power supply. This is how it is written, described and measured. For example, if you calculate the magnetic field caused by a current – the direction of the current is in the positive direction towards the negative. In other words, in your example, current flows from the red (or yellow) thread through the load and in black.
If you go beyond the concept of bulk flow into the wire and look at how real current is done then things get more complicated. In metal, electricity is transported by electrons. Electrons have a negative charge, so the physical direction the electrons are moving must be opposite to the current flow direction.
Electric current is not always carried by electrons. If you pass an electric current through a substance such as molten salt (sodium chloride), then half of the current is transported by positively charged sodium ions.
They flow in the conventional direction of the current – from positive to negative – and gather at the negative electrode, where they collect electrons from the electrode and form sodium metal (and so does metallic sodium). The negative chloride ions carry the other half of the current and flow in the reverse direction (like the electrons) from negative to positive (where their electrons have excess in the electrode and form chlorine gas).
