Question

When electrons drift in a conductor from lower to higher potential, does it mean that all the ‘free electrons’ of the conductor are moving in the same direction?

Answer 1

When electrons drift in a conductor from lower to higher potential, it is important to understand the behavior of the free electrons in the conductor. Let's break this down:

1. Electron Drift in a Conductor:

In a conductor, free electrons are constantly moving in random directions due to thermal energy. When an electric field is applied (such as when a potential difference is applied across the conductor), these free electrons experience a force that causes them to "drift" in the direction opposite to the applied electric field. Since electrons are negatively charged, they move from the region of lower potential to the region of higher potential. This is due to the force exerted by the electric field.

2. Are All Free Electrons Moving in the Same Direction?

While the majority of free electrons do indeed drift in the direction from lower to higher potential (opposite to the electric field), it is important to note that not all free electrons are moving in the same direction at any given time.

• Electrons still experience random thermal motion in addition to their drift motion. This random thermal motion means that individual electrons are constantly moving in random directions at high speeds (often much faster than the drift velocity).
• The overall drift of the electrons is a result of their superposition, where the random motion averages out, but the drift due to the electric field is in one direction.
• Thus, while there is a net drift of electrons from lower to higher potential (opposite the electric field), their individual random motions make it so that not all electrons are moving in the same exact direction at every moment.

3. Conclusion:

No, not all the free electrons in a conductor are moving in the same direction when they drift under an applied electric field. While there is a net drift in the direction from lower to higher potential, their random thermal motion causes them to move in various directions. The drift represents a small, net motion superimposed on their random movement.