Derive the expression for drift velocity of free electron in terms of relaxation time and electric field applied across a conductor.

Explanation

To derive the expression for drift velocity (\( V_d \)) of free electrons in terms of relaxation time (\( \tau \)) and the electric field (\( E \)) applied across a conductor, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the System**:
- Consider a conductor with free electrons. When an electric field \( E \) is applied, it exerts a force on the electrons, causing them to drift in the direction opposite to the electric field.

2. **Force on an Electron**:
...