A metal wire of uniform mass density having length $L$ and mass $M$ is bent to form a semicircular arc and a…
- $\frac{\mathrm{GmM} \pi^2}{\mathrm{~L}^2}$
- $\frac{\mathrm{GMm} \pi}{2 \mathrm{~L}^2}$
- $0$
- $\frac{2 \mathrm{GmM} \pi}{\mathrm{L}^2}$
Solution

We have $R=\frac{L}{\pi}$ $\begin{aligned} & \mathrm{g}_0=\frac{2 \mathrm{G} \frac{\mathrm{M}}{\mathrm{L}}}{\mathrm{R}}=\frac{2 \mathrm{GM} \pi}{\mathrm{L}^2} \\ & \therefore \mathrm{F}_{\mathrm{m}}=\mathrm{mg}_0=\frac{2 \mathrm{GM} \pi \mathrm{m}}{\mathrm{L}^2} \end{aligned}$
Hence option (4)
Asked in: JEE Main 2024 (04 Apr Shift 1)