Why should the potentionmeter wire be of uniform cross-section and composition?

Why should the area of cross section of metre bridge wire be uniform?

In the circuit shown in the figure, AB is a resistance wire of uniform cross-section in which a potential gradient of 0.01V^-1 exists. If the galvanometer G shows zero deflection what is the e.m.f. E_1 of the cell used?

In the circuit shown in the figure, AB is a resistance wire of uniform cross-section in which a potential gradient of 0.01Vcm^-1 exists. If the internal resistance of the deriver cell increases on some account, how will it change the balance point in the experiment?

Resistivity of the material of a conductor of uniform cross-section varies along its length as rho=rho_(0)(1+alpha x) . Find its resistance if its length is L and area of cross-section is A.

The resistivity of potentiometer wire is 10^-7 ohm m and its area of cross-section is 10^-6m^2 . When a current I = 0.1. A flows through the wire, its potential gradient is

A 5m long wire is used with uniform area of cross-section and 50 ohm resistance inpotentiometer.The wire is connected in series with a battery of 10V along with external resistance 450ohm. If unknown emf E is balanced at 4m length of wire, find potential gradient of potentiometer wire and value of unknown emf

Why should weeds be removed?

When a wire of uniform cross-section a, length l and resistance R is bent into a complete circle, resistance between any two of diameterically opposite points will be

A straight thick long wire of uniform cross-section of radius a is carrying a steady current I. Calculate the ratio of magnetic field at a point a//2 above the surface of the wire to that at a point a//2 below its surface. What is the maximum value of the field of this wire?