Identify the correct statements about the internal resistance of a cell
(A) It depends on the nature of the electrolyte
(B) It increases with the increase in temperature of the electrolyte
(C) It increases with the decrease in temperature of the electrolyte
(D) It increases with the distance between the two electrodes
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A), (C) and (D) only
The internal resistance of a cell is the resistance offered by the electrolyte to the flow of ions between the two electrodes. Like any conductor, it depends on how freely the ions move and on the length and area of the electrolyte path.
(A) It depends on the nature of the electrolyte — Correct. Different electrolytes have different ionic conductivities, so the internal resistance changes with the electrolyte (and its concentration).
(B) It increases with the increase in temperature of the electrolyte — Incorrect. On heating, the ions move more freely, so the resistance of the electrolyte decreases.
(C) It increases with the decrease in temperature of the electrolyte — Correct. On cooling, the ions move less freely and the internal resistance rises.
(D) It increases with the distance between the two electrodes — Correct. A larger separation means a longer path through the electrolyte, and resistance is proportional to the length of the path.