A 25 kg uniform solid sphere with a 20 cm radius is suspended by a vertical wire such that the point of suspension is vertically above the centre of the sphere. A torque of 0. l0 N-m is required to rotate the sphere through an angle of 1.0 rad and then maintain the orientation. If the sphere is then released, its time period of the oscillation will be:

 

• A

  $\mathrm{\pi } \mathrm{second}$

• B

  $\sqrt{2} \mathrm{\pi } \mathrm{second}$

• C

  2$\mathrm{\pi } \mathrm{second}$

• D

  $4\mathrm{\pi } \mathrm{second}$