JEE Main 2023 — Experimental Physics Question with Solution

A meter bridge consists of a wire of length $1 \mathrm{m}$ and of uniform cross-sectional area stretched taut and clamped between two thick metallic strips bent at right angles with two gaps across which resistors are to be connected. It works on the principle of the Wheatstone bridge. Therefore, we can write

$$\begin{gathered} \frac{R_1+R_2}{10}=\frac{60}{40} \\ \Rightarrow R_1+R_2=15 \Omega \end{gathered}$$

Then for the second case, we can write 

$$\begin{gathered} \frac{R_1{R}_2}{\left(R_1+R_2\right)\times 3}=\frac{40}{60} \\ \Rightarrow R_1{R}_2=30 {\Omega }^2 \end{gathered}$$