Question

What is the advantage of using thick metallic strips to join wires in a potentiometer

Answer 1

As we know, resistance is given by,

$R=\frac{\rho l}{A}$

Therefore, as the area of cross section of the wire increases (thick wire), the resistance of the wire decreases. Thus, metallic strips have very low resistance and can be ignored while measuring the length of the wire used to determine null point.

One measures only their lengths along the straight segments (of lengths 1 meter each). This is easily done with the help of centimeter rulings or meter ruler and leads to accurate measurements.

Final Answer: Resistance of the wire can be ignored, while measuring the length of wire.