With increase in cross sectional area the number of atoms with which electrons will collide will also increase in the same proportion. So basically the resistance shouldn't change with increasing wire thickness. Then why is it inversely proportional to cross sectional area?
[Physics] Why electrical resistance decreases with cross sectional area
collisionelectric-circuitselectric-currentelectrical-resistanceelectricity
Best Answer
Think of cross-sectional area as consisting of numerous individual wires in parallel. Adding more wires in parallel decreases the resistance of that circuit path. So, bigger cross sectional area = more wires in parallel = lower resistance.