question_answer

Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities \[{{\omega }_{1}}\] and \[{{\omega }_{2}}\]. They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is                              [NEET-2017]

A) \[\frac{l}{8}{{({{\omega }_{1}}-{{\omega }_{2}})}^{2}}\]

B) \[\frac{1}{2}l{{({{\omega }_{1}}+{{\omega }_{2}})}^{2}}\]

C) \[\frac{1}{4}l{{({{\omega }_{1}}-{{\omega }_{2}})}^{2}}\]

D) \[l{{({{\omega }_{1}}-{{\omega }_{2}})}^{2}}\]

Correct Answer: C

Solution :

[c]