With the help of a potentiometer, we can determine the value of the emf of a given cell. The sensitivity of the potentiometer is:
Statements: (A) Directly proportional to the length of the potentiometer wire (B) Directly proportional to the potential gradient of the wire (C) Inversely proportional to the potential gradient of the wire (D) Inversely proportional to the length of the potentiometer wire
Find the number of correct statement(s).
Correct answer:2
Standard Method
Given: A potentiometer is used to determine the emf of a given cell.
Find: The statements that correctly describe the sensitivity of the potentiometer.
The sensitivity of the potentiometer is defined as the smallest potential difference that can be measured.
It is directly proportional to the length of the potentiometer wire, so a longer wire gives higher sensitivity.
It is inversely proportional to the potential gradient of the wire, so a lower potential gradient gives higher sensitivity.
Therefore, the correct statements are A and C. The correct option is A,C.
Assuming sensitivity is directly proportional to potential gradient. This is wrong because a larger potential gradient means a larger potential drop per unit length, which reduces the ability to measure small potential differences. Use the inverse relation instead.
Confusing sensitivity with total potential drop across the wire. A longer wire increases balancing length for a small emf and hence improves sensitivity. Do not treat wire length as reducing sensitivity.
Get unlimited AI-adaptive practice, mastery tracking, and an AI tutor that explains every step — free to start.
