Physics · 2019
JEE Main · 10 January 2019, Shift 1 · Q29
A potentiometer wire A B having length L and resistance 12 r is joined to a cell D of emf ε and internal resistance r. A cell C having emf ε / 2 and…
A potentiometer wire $\displaystyle A B$ having length $\displaystyle L$ and resistance $\displaystyle 12$ r is joined to a cell D of emf $\displaystyle \varepsilon$ and internal resistance r . A cell C having emf $\displaystyle \varepsilon / 2$ and internal resistance $\displaystyle 3 r$ is connected. The length AJ at which the galvanometer as shown in fig. shows no deflection is :
Official answer
(1)
$\displaystyle \frac{13}{24} \mathrm{~L}$
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JEE Main 2019 Physics question, with the answer from NTA’s final answer key. Where our answers come from.