(i) State the principle of working of a potentiometer.
(ii) In the following potentiometer circuit AB is a uniform wire of length 1 m and resistance `10Omega`
Calculate the potential gradient along the wire and balance length AO (=l)

Explanation

When a constant current flows through a conductor of uniform area of cross-section, the potential drop across any length of the wire is directly proportional to the length, i.e., V `alpha` l