Question

What happens to the dirft velocity and resistance of the conductor if length of the conductor is doubled keeping potential difference unchanged.

Answer 1

Drift velocity varies inversely proportional to the length of the conductor.
$V_d\infty \frac{1}{L}$
If length of the conductor is doubled, drift velocity becomes half.

Resistance of the conductor varies directly proportional to the length of the conductor.
If length of the conductor is doubled, resistance becomes doubled.