Physics · 2020
JEE Main · 2 September 2020, Shift 2 · Q20
A potentiometer wire PQ of 1 m length is connected to a standard cell E_1. Another cell E_2 of emf 1.02 V is connected with a resistance ' r ' and…
A potentiometer wire PQ of $\displaystyle 1$ m length is connected to a standard cell $\displaystyle \mathrm{E}_1$. Another cell $\displaystyle \mathrm{E}_2$ of emf $\displaystyle 1.02$ V is connected with a resistance ' $\displaystyle r$ ' and switch S (as shown in figure). With switch S open, the null position is obtained at a distance of $\displaystyle 49$ cm from Q. The potential gradient in the potentiometer wire is :
Official answer
(2)
$\displaystyle 0.02 \mathrm{~V} / \mathrm{cm}$
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JEE Main 2020 Physics question, with the answer from NTA’s final answer key. Where our answers come from.