# How will current flow in this simple circuit?

I read that current flows in all available paths, so when (blue) current flows from the generator it will divide into (red) and (green) at point A.

Why doesn't the (green) current flow in all available paths at point B (flow in the opposite direction of red.)

My friend told me that current flows through the path with the least resistance but I read in google that some small amount of current will still flow through all of the paths.

• Current flows from high voltage to low voltage. The green current doesn't back-track through the resistor because the voltage at the other end is higher. Commented Oct 15, 2022 at 15:53
• What kind of receptor are you referring to? Commented Oct 15, 2022 at 16:17

Current does not only flow from high potential to low potential. In order to flow in a complete circuit, it must flow from high potential to low potential in part of the circuit and from low potential to high potential in other parts of the circuit.

However it can only flow from low potential to high potential when the device it is flowing through is able to generate electrical energy (For example in a battery). It flows from high potential to low potential in devices that consume energy from the circuit.

Since resistors only consume electrical energy, converting it to heat, and never generate electrical energy, currents in resistors must be from high potential to low potential.

• does current flowing from low to high end apply also to components that play both roles of the source and consumers (like capacitors) Commented Oct 15, 2022 at 22:58
• @forphone, yes, when a device is absorbing energy current will be flowing through it from positive to negative and vice versa. Commented Oct 16, 2022 at 1:29

The current travels only from higher potential to lower potential, it never travels to higher potentials, so if at (B) it cannot go back to (A) since it has a higher potential.

• It does travel from low to high voltage in the battery. It can't flow in a complete circuit if it doesn't flow from low to high in part of its path. Commented Oct 15, 2022 at 17:11
• Well, the battery is special device that makes this trick happens to overcome potential difference, thsts due chemical reaction, eventually the battery has capacity and dies and no longer can do this. Commented Oct 15, 2022 at 17:28
• Nonetheless, there must be some component in every circuit that is capable of that trick or the circuit would not work. We can't tell new learners on day 1 "current always flows in complete circuits" and then tell them the next day "current flows only from positive to negative potential". We shouldn't forget that the power source is part of the circuit too and follows the same rules as other components (aside from generating electrical energy rather than consuming it). Commented Oct 15, 2022 at 17:30
• I see your post and how you classify energy generator and energy consumer and the fact current flaw shouldn't be disturbed , it is very clear and straight forward, thanks! Commented Oct 15, 2022 at 17:36

I read that current flows in all available paths

Current flows in all the available paths providing that flow is from a positive potential to a negative potential. That's our "sensible and practical" low frequency "model" that isn't designed or intended to take account of the finite speed of light and transmission-line theory.

If we did, you'd stand a chance of arguing a good case for the current splitting at point B.

My friend told me that current flows to the path with the least resistance but I read in google that some small amount of current will still flow to all the paths.

Current will take all viable paths else how could current flow in two parallel resistors when one of the resistors was 1 Ω greater than the other.

• I think you should say "Conventional current flows in all the available paths ..."
– Rodo
Commented Oct 15, 2022 at 17:39
• If I said conventional current, it would be a tautology. If I said conventional current in order to make the distinction between electron flow and current flow then that might be a partially good reason to do as you suggest. This question is tagged "current" and "circuit analysis" both of which imply non-electron flow. If I agreed with you I would have to change thousands of answers I have previously given on this site to add the superfluous term "conventional" AND change the "current" tag <-- people will object so, maybe you should rethink this request @Rodo Commented Oct 15, 2022 at 17:44
• @Rodo additionally, if I said conventional current flows in all the available paths I would be implying that electron flow doesn't. People would get confused. Commented Oct 15, 2022 at 17:47
• Yes to "make the distinction between electron flow and current flow". Your answer says "flow is from a positive potential to a negative potential". That implies conventional current flow. It is ok to clarify conventional vs electron flow when someone ask this types of questions. I just want to make newbies aware that there is a difference and the electrical engineering symbols refer to conventional current and not electron flow.
– Rodo
Commented Oct 16, 2022 at 0:11

The only things flowing in the circuit are electrons. Current doesn't flow. Current is flow.

The electrons flow in the circuit external to the battery from the negative terminal to the positive terminal.

Electrons will flow in a branch according the the electric field along the branch. According to the diagram the electric field is more positive at A relative to B, so the electrons will flow from B to A.

Internal to the battery: Negative ions flow toward the positive terminal. Positive ions flow toward the negative terminal. For me this is an interesting visualization.

Andre-Marie Ampere traced current around a circuit with a compass. He found that the compass deflected in the same direction whether tracing the circuit external the the voltaic pile or the circuit internal to it. Electrons and protons had not been discovered yet, but the scientists of the day new about positive and negative charge.

Eventually the direction for conventional current was set as the direction of charge flow that produce the same magnetic deflection as does the flow of positive charge. This means that positive charge flowing in one direction produce the same magnetic field as negative charge flowing opposite.

So therefore the current in the branch with the red arrows will be in the direction from A to B because the electric field along the branch will move the electrons from B to A.

• You're right that "current is flow." However, we colloquially say things like the current flows down the river all the time without any misunderstanding. Commented Oct 15, 2022 at 22:03
• @ErikR: There are many phrases that are used colloquially without misunderstanding. "All the time" is a stretch. There are many that use terms and phrases correctly. "The current is downstream" is also used. In electronics there are two quantities that flow: positive charge and negative charge. Where they flow in opposite directions, the current is the same. These questions result in a flurry of answers partly because of the misunderstanding. Commented Oct 15, 2022 at 22:21

Current flows from a higher potential to a lower potential using all possible paths. In the diagram, A to B using shortest path and also through longest path.Due to symmetry of the circuit, these currents would be equal. These two currents combine at B and according to KCL,the total current would flow back into the negative terminal of voltage source.