A metal rod of length `'L'` and mass `'m'` is piovted at one end. A thin disk of mass `'M'` and radius `'R' (lt L)`. Is attached at its centre to the free end of the rod. Consider two ways the disc is attached: (case `A`). The disc is not free to rotate about its centre and (case `B`) the disc is free to rotate about its center. The rod-disc sustem perform `SHM` in vertical plane after being released from the same displaced potion. Which of the following statement(s) is (are) true?

Options

A. Restoring torque in case `A` = Restoring torque in case`B`
B. Restoring torque in case `A lt` Restoring torque in case`B`
C. Restoring frequency case `A gt` Angular frequency for case`B`
D. Restoring frequency case `A lt` Angular frequency for case`B`

Answer

A, D

Explanation

Tprque is same for both the cases.
`T = 2pisqrt((I)/(mgd))`
`I_(A) gt T_(B)`
`omega_(A) lt omega_(B)`