Question

Do conventional current and electron current flow in the same direction in an electric circuit?

Answer 1

The short answer is: No, they flow in opposite directions.

Here is a detailed breakdown of why:

1. Electron Current (The Physical Reality)

In a typical electric circuit with metal wires (like copper), the charge carriers that are free to move are electrons.

• Electrons have a negative charge.
• The negative terminal of a power source (like a battery) has an excess of electrons, and the positive terminal has a deficit.
• Since like charges repel and opposite charges attract, the negatively charged electrons are repelled from the negative terminal and attracted to the positive terminal.

Therefore, electron current flows from the negative terminal, through the circuit, to the positive terminal. This is what is actually happening inside the wires.

2. Conventional Current (The Historical Convention)

The concept of electricity was studied long before the electron was discovered in 1897. Scientists like Benjamin Franklin had to make an educated guess about the nature of electric flow.

• They theorized that electricity was a type of "fluid" that flowed from an area of high pressure (positive) to an area of low pressure (negative).
• They defined the direction of current as the direction a positive charge would move.

Therefore, conventional current flows from the positive terminal, through the circuit, to the negative terminal.

Why Do We Still Use the "Wrong" Convention?

By the time the electron was discovered and it was realized that the charge carriers in metals were negative and moved the "wrong" way, the conventional current model was already deeply established.

• Legacy: All the formulas (like Ohm's Law, $V=IR$), rules (like Kirchhoff's Laws), and component symbols (the arrow on a diode or transistor) had been designed around the idea of current flowing from positive to negative.
• Practicality: Changing the convention would require rewriting every textbook and retraining generations of engineers and technicians for very little practical benefit. For most circuit analysis, it doesn't matter which direction you use, as long as you are consistent. The math works out the same either way.
• It's Not Always "Wrong": In some cases, like the flow of positive ions in a solution (electrochemistry) or "holes" in a semiconductor, the charge carriers are indeed positive, and they move in the direction of conventional current.

Summary Table

| Feature | Conventional Current | Electron Current (Electron Flow) |
| -------------------- | --------------------------------------------------- | ------------------------------------------------ |
| Direction of Flow | Positive (+) to Negative (-) | Negative (-) to Positive (+) |
| Charge Carrier | Assumed to be positive charges | Actual moving electrons (negative charge) |
| Basis | Historical convention from before the electron's discovery | The physical reality in metal conductors |
| Common Use | Most engineering, circuit diagrams, and formulas | Solid-state physics, chemistry, and introductory explanations |

Conclusion: When you look at a circuit diagram (schematic), all the arrows and calculations are based on conventional current (positive to negative). However, if you want to understand the physics of what's happening inside the wire, you need to think about electron current (negative to positive).