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JEE Advanced2024PhysicsRotational MotionActual

A disc of mass M and radius R is free to rotate about its vertical axis as shown in the figure. A battery operated motor of negligible mass is fixed to this disc at a point on its circumference. Another disc of the same mass M and radius R / 2 is fixed to the motor's thin shaft. Initially, both the discs are at rest. The motor is switched on so that the smaller disc rotates at a uniform angular speed . If the angular

Correct answer

0

Step-by-step solution

On applying conservation of angular momentum about axis of larger disc. aligned & 1 2 M ( R 2 )^2 - M ( ^ R ) R - MR ^2 2 ^ =0 & 8 = 3 ^ 2 & ^ = 12 Hence, n =12 aligned

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