how do the resistance and drift velocity changes if:a)V(potential difference) is doubled b)lentgh is doubled c)area is halved of a conducting rod

 

v_d=eE?/m=eV?/ml

So if (1)V is doubled then the drift velocity also doubles.

(2)l is doubled then dr vel decreases.

(3)dr vel is independent of area of cross section.

 

Resistance (R=ml/ne²A?)of the conductor (1)does not change with the applied V.

(2) R gets doubled as length doubles.

(3)gets doubled as area of cross section gets halved.