Q 11-04-105JEE MainJEE Main 2023 (30 Jan, Shift 2)Easy
A block of $\sqrt3\ \text{kg}$ is attached to a string whose other end is attached to the wall. An unknown force $F$ is applied so that the string makes an angle of $30^\circ$ with the wall. The tension $T$ is (Given $g=10\ \text{m s}^{-2}$)
Answer: (A) $20\ \text{N}$
At the junction, vertical balance: $T\cos30^\circ=mg=10\sqrt3\ \text{N}$.
$$T=\frac{10\sqrt3}{\sqrt3/2}=20\ \text{N}$$
Solution by Sreeraj P, M.Sc Physics