Answer the following:
`(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

### Solution:

**(i)** To derive an expression for the drift velocity of free electrons, we start with the following concepts:

1. **Electric Field and Force on Electrons**: When a potential difference (V) is applied across a conductor, an electric field (E) is established. The electric field can be expressed as:
\[ E = \frac{V}{L} \]
...