The resistivity and conductivity of an ionic solution can be measured using a conductivity cell which uses alternating current. The resistance of the solution is given by the formula R =

Where

l is the distance between the electrodes,

A is the area of cross section of cell.

The term is known as the cell constant.

It depends on the length and area of cross section of cell, hence it remains constant for a cell, regardless of nature of electrolyte.

The correct option is (iv).