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 inthe same direction?

Hint:

Electron drift in a conductor represents a net motion in one direction due to the applied electric field, but the individual electrons still exhibit random motion due to thermal energy.

Answer 1

To address the question, we need to understand the behavior of free electrons in a conductor when subjected to an electric field.

1. Understanding the Concepts: 

- Free Electrons: In a conductor, free electrons are those that are not bound to a particular atom and can move freely through the material. These electrons are responsible for the flow of current when an electric field is applied.

- Drift Velocity: When an electric field is applied across a conductor, the free electrons experience a force that causes them to drift towards the higher potential. This movement of electrons is called the "drift velocity" and is generally very slow compared to the speed of the individual random motion of the electrons.

- Electric Potential: The electric potential is higher at the end of the conductor where the electric field is applied. Electrons, being negatively charged, move from regions of lower potential to higher potential under the influence of the electric field.

2. Do All Free Electrons Move in the Same Direction?

- While electrons drift from lower to higher potential, not all free electrons in the conductor are moving in the same direction at any given instant. The reason for this is the nature of the random thermal motion of the electrons. Each electron has its own random motion due to its thermal energy, which is much faster than the drift motion caused by the electric field.

- The overall drift velocity, which is the net movement of electrons due to the applied electric field, is very small and is in the direction from lower to higher potential (opposite to the electric field). However, the individual electrons still undergo random motion in all directions, which results in a random distribution of velocities.

3. Conclusion:

No, not all the free electrons move in the same direction. The electrons experience random motion due to thermal energy, but they drift overall in the direction opposite to the electric field due to the applied potential difference.

Final Answer:

While electrons drift in the direction from lower to higher potential, their random thermal motion means that not all of the free electrons are moving in the same direction at any given moment.