Physics · 2025
JEE Main · 28 January 2025, Shift 1 · Q27
A bead of mass 'm' slides without friction on the wall of a vertical circular hoop of radius 'R' as shown in figure. The bead moves under the…
A bead of mass 'm' slides without friction on the wall of a vertical circular hoop of radius 'R' as shown in figure. The bead moves under the combined action of gravity and a massless spring (k) attached to the bottom of the hoop. The equilibrium length of the spring is 'R'. If the bead is released from top of the hoop with (negligible) zero initial speed, velocity of bead, when the length of spring becomes 'R', would be (spring constant is 'k', g is accleration due to gravity)
Official answer
From NTA’s final answer key for this paper.
(4)
$\displaystyle \sqrt{3 R g+\frac{k R^2}{m}}$
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JEE Main 2025 Physics question, with the answer from NTA’s final answer key. Where our answers come from.