Why electrons flow opposite to conventional current flow. “In-depth Animation”

Summary

The video explains how electric current flows through a wire, starting with the properties of copper atoms and how the movement of electrons creates current. It details the behavior of free electrons and the effect of an electric field created by a battery's terminals. The video addresses common misconceptions, such as the historical understanding of current flow direction, and emphasizes the importance of understanding fundamental concepts for deeper learning in electrical engineering. The speaker encourages viewers to explore advanced topics and choose quality educational resources to further their knowledge.

Takeaways

• 🔋 The video explains how electricity or current flows inside a wire when a battery is connected.
• ⚛️ A copper atom contains 29 protons, 29 electrons, and 35 neutrons, with only one electron loosely bound in the outermost shell.
• 🔄 When a battery is connected, it pushes extra electrons from the negative terminal and pulls electrons from the positive terminal, creating an electric field.
• 🔌 The imbalance caused by the extra electrons makes them relocate, causing movement throughout the wire.
• 🚀 Free electrons are created when the outermost electrons are repelled by incoming electrons, leading to current flow.
• 🌀 The repulsion between electrons in the wire causes them to move in a specific direction, with horizontal space allowing more movement than vertical.
• ⚙️ Positive charges (protons) do not move, but the removal of electrons from atoms near the positive terminal causes them to become positively charged.
• 🔄 The push from extra electrons and the pull from positive charges cause a coordinated motion of electrons, which is how current flows.
• 🌩️ The electric field forms from the positive to the negative terminal, guiding the movement of electrons.
• 📜 The video also touches on historical concepts, explaining that early scientists like Benjamin Franklin thought positive charges moved, which led to the concept of 'conventional current,' opposite to the flow of electrons.

Q & A

What happens to the copper atom's outer electron in the absence of a battery?

In the absence of a battery, the outer electron of a copper atom is loosely attached to the nucleus due to the weaker force of attraction. However, the atom remains stable and neutral, with equal numbers of protons and electrons.

How does the battery create an electric field in the wire?

When a battery is connected, its negative terminal pushes extra electrons into the wire, while the positive terminal pulls electrons from the wire, creating an imbalance. This imbalance forces electrons to relocate, forming an electric field that drives the movement of electrons.

Why do electrons become free when extra electrons enter the wire?

When extra electrons enter the wire, they exert a repulsive force on the electrons already present. This force weakens the bond between the outer electrons and their atoms, allowing them to move freely and become 'free electrons.'

In what direction do electrons move within the wire, and why?

Electrons move in the horizontal direction because there is more free space in that direction, whereas in the vertical direction, they are constrained by the limited space within the wire.

How does the 'push and pull' analogy relate to the movement of electrons in a wire?

The 'push and pull' analogy explains that while the extra electrons push other electrons forward, the positive terminal of the battery pulls electrons from the wire. This coordination of forces enables the electrons to move continuously through the wire.

What happens to atoms near the positive terminal of the battery when electrons are pulled away?

When electrons are pulled away from atoms near the positive terminal, these atoms become positively charged because they lose their balance between protons and electrons. To stabilize themselves, they pull electrons from neighboring atoms, continuing the cycle.

What role does the positive terminal of the battery play in the electric field?

The positive terminal creates a positive charge in the wire by pulling electrons away from atoms, which generates an electric field. This field moves from the positive to the negative terminal, guiding the flow of electrons.

What is the difference between conventional current and electron flow?

Conventional current refers to the flow of positive charge, which is in the opposite direction of electron flow. Benjamin Franklin originally defined current as the flow of positive charges, and this convention is still used today, despite the fact that electrons are actually the particles in motion.

How does the process of electron movement in the wire happen so quickly?

The movement of electrons happens almost instantaneously because the extra electrons push others forward while the positive charge pulls them, creating a continuous and rapid flow. This entire process occurs in just fractions of a second.

Why is it important to understand current flow as both conventional and electron flow?

Understanding both conventional and electron flow is crucial because many established equations and principles, derived historically, are based on the concept of conventional current. However, modern science recognizes that electrons are the true carriers of electric charge.