A string breaks if its tension exceeds $10$ newtons. A stone of mass $250\, gm$ tied to this string of length $10 \,cm$ is rotated in a horizontal circle. The maximum angular velocity of rotation can be .......... $rad/s$
A$20$
B$40$
C$100 $
D$200$
Medium
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A$20$
a (a) $T = m{\omega ^2}r$
$⇒$ $10 = 0.25 \times {\omega ^2} \times 0.1$
$⇒$ $\omega = 20\,rad/s$
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