Physics · 2022
JEE Main · 28 July 2022, Shift 1 · Q55
As shown in the figure, a potentiometer wire of resistance 20 Ω and length 300 cm is connected with resistance box (R.B.) and a standard cell of emf…
As shown in the figure, a potentiometer wire of resistance $\displaystyle 20 \Omega$ and length $\displaystyle 300$ cm is connected with resistance box (R.B.) and a standard cell of emf $\displaystyle 4$ V . For a resistance 'R' of resistance box introduced into the circuit, the null point for a cell of $\displaystyle 20$ mV is found to be $\displaystyle 60$ cm. The value of 'R' is \_\_\_\_ $\displaystyle \Omega$.
Official answer
780
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