21 Potentiometer is an apparatus used for measuring the emf

Last updated: 6/12/2023

21 Potentiometer is an apparatus used for measuring the emf of a cell or potential difference between two points in an electrical circuit accurately It is also used to determine the internal resistance of a primary cell The potentiometer is based on the principle that if V is the potential difference across any portion of the wire of length 1 and resistance R then V x 1 or V kl where k is the potential gradient Thus potential difference across any portion of the wire of length is directly proportional to length of the wire of that portion The potentiometer wire must be uniform The resistance of potentiometer wire should be high Primary circuit Secondary circuit A i Which one of the following is true about potentiometer a Its sensitivity is low b It measures the emf of the cell very accurately