A string of length L is fixed at one end and carries a mass of M at the other end. The mass makes (3/π ) rotations per second about the vertical axis passing through end of the string as shown. The tension in the string is ML.A string of length L is fixed at one end and carries a mass of M at the other end. The mass makes (3/π ) rotations per second about the vertical axis passing through end of the string as shown. The tension in the string is ML.. images

Physics · Horizontal Circular Motion

JEE Main 2025 — 24 January, Evening Shift — Question 65

A string of length $L$ is fixed at one end and carries a mass of M at the other end. The mass makes $\left(\frac{3}{\pi}\right)$ rotations per second about the vertical axis passing through end of the string as shown. The tension in the string is $\qquad$ ML.A string of length $L$ is fixed at one end and carries a mass of M at the other end. The mass makes $\left(\frac{3}{\pi}\right)$ rotations per second about the vertical axis passing through end of the string as shown. The tension in the string is $\qquad$ ML.. images

Answer: 36

Numerical answer — enter this value.

Step-by-step solution

$\mathrm{T} \cos \theta=\mathrm{mg}$

$\mathrm{T} \sin \theta=\mathrm{M} \omega^{2} \mathrm{R}$

Using equation (2)

$\mathrm{T} \sin \theta=\mathrm{M} \omega^{2}(\mathrm{~L} \sin \theta)$

$\mathrm{T}=\mathrm{M} \omega^{2} \mathrm{~L}=\mathrm{M}\left(\frac{3}{\pi} \times 2 \pi\right)^{2} \mathrm{~L}$

$\mathrm{T}=36 \mathrm{ML}$

Answer key and solution verified before publishing.

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Exam: JEE Main 2025
Paper: 24 January, Evening Shift
Subject: Physics
Chapter: Horizontal Circular Motion
Topic: Problems involving application of circular motion