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A spool of mass M and radius 2 R lies on an inclined plane as shown in figure. A light thread is wound around the connecting tube of the spool and its free end carries a weight of mass m . The value of m so that system is in equilibrium is

Options

  1. A2 Msinα
  2. BMsinα
  3. C2 Mtanα
  4. DMcosα

Correct answer

A. 2 Msinα

Step-by-step solution

Equilibrium of m give T = mg ( T = Tension in string) Net torque about point of contact of the spool should be zero. Hence, ( 2 R ) ( Mgsinα ) = TR or 2 Mgsinα = mg or m = 2 Msinα

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