Q 12-03-039NEETJEE MainMedium
A potentiometer wire $4$ m long has a potential difference of $2$ V across it. A cell balances at $2.5$ m. Its emf is
Answer: (D) $1.25$ V
Potential gradient $= \dfrac{2}{4} = 0.5$ V/m. $E = 0.5 \times 2.5 = 1.25$ V.
Solution by Sreeraj P, M.Sc Physics