`(i)` Derive an expression for drift velocity of free electrons.
`(ii)` How many drift velocity of electrons in a metallic conductor vary with increase in temperature ? Explain.

Explanation

### Step-by-Step Solution

#### (i) Derivation of Expression for Drift Velocity of Free Electrons

1. **Understanding the Concept**:
- When a potential difference (V) is applied across a conductor, an electric field (E) is created, causing free electrons to move and generate a current.

2. **Force on Electrons**:
...