The length of a potentiometer wire is $\ell $. A cell of emf $E$ is balanced at a length $\ell /3$ from the positive end of the wire. If the length of the wire is increased by $\ell /2$ at what distance will the same cell give a balanced point
A$\frac {2\ell }{3}$
B$\frac {\ell }{2}$
C$\frac {\ell }{6}$
D$\frac {4\ell }{3}$
Medium
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B$\frac {\ell }{2}$
b $\mathrm{E}=\mathrm{x} \ell_{1}=\frac{\mathrm{V}}{\ell} \ell_{1}=\frac{\mathrm{V}}{\ell}\left(\frac{\ell}{3}\right)$ ..........$(1)$
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