Theoritically,current is carried by electrons which are smallest particles in atomic structure.see this picture.In chemical combination,all types of reactions,they are transfered between each other depending on the types of chemical bonds.For current,electrons are flowing form high potential to low potential nodes.Current is measured by ampere(A).In this way,electron flowing becomes current.To become a current,there should have potential difference.
What is potential difference?
Potential difference is the work done needed to cause the motion of a unit electric charge between two points. V = W/q, in which V is potential difference, W is work, and q is charge.
In work done,W=Fs for horizontal montion,W=mgh for vertical motion,W=Vq for electrical motion,they are normally same in theoritical construction of equation.
Ok,let focus on how does current flow.
Do you believe current flow from positive to negative terminal?
Conventional Vs electron flow
We have known current flows from positive terminal to negative terminal.Actually,that is just the assuming of Benjamin Franklin.Actually,current flows from negative terminal to positive one.
Because,we have known only electron can move in atomic structure,in which other particles like neutron and proton are strongly bounded in nucleus.There is an attraction between positive and negative atom.For positively charged atom,that means electrons are less than protons in amount.That's why that atom is positively charged.
For Battery,electron flows from negative terminal to positive one since there is an attraction between positive node and negative one,that can also be called potential difference.But,we are still using the concept of flowing + to -.All circuit equations are based on that concept.So,Why isn't it wrong in calculating?Because,that is only wrong in direction but true in other Theoritical Concept.This is referred to as “conventional flow”, while the physically-correct opposite assumption is referred to as “electron flow”. Generally, electricians and similar low-level electrical workers tend to use conventional flow, while electron flow tends to be more widely used among the higher fields of electronics.
