Home › CBSE Class 11 › Physics › Systems of Particles and Rotational Motion › Per NCERT §6.11 (frictionless rigid body), the w…
Per NCERT §6.11 (frictionless rigid body), the work done by an external torque equals which?
AHeat dissipated
BLoss due to friction
CZero in steady rotation
DThe change in rotational KE
Answer & Solution
Correct answer: D. The change in rotational KE
NCERT §6.11: no internal motion, no friction ⇒ τω = d/dt((1/2)Iω²) ⇒ W_ext = ΔK_rot. Work-energy theorem in rotation.
Related questions
The radius of gyration relates the moment of inertia to the body's:The kinetic energy of a rolling body is the sum of translation and:Rotation about a fixed axis is directly analogous to:The parallel axes theorem adds to the centre of mass value the mass times:In the moment of inertia formula, r is the distance from the axis that is:The centre of gravity is where the total gravitational torque is:Rotational equilibrium requires the total external torque to be:Translational equilibrium requires the total external force to be: