29 public questions tagged with this topic.
The motion of any point is a combination of the translational velocity of the body (same for all points) and the rotational velocity about the axis, varying with distance from the axis.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
For mechanical equilibrium, both translational and rotational equilibrium are required: the net force (∑F = 0) and net torque (∑τ = 0) must be zero. As per NCERT, applying relevant law/formula with correct units and sign convention leads to Both net force and net torque must be zero. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
If the net external torque is zero (dLdt = τ = 0), angular momentum is conserved, and for a fixed moment of inertia, angular velocity remains constant. As per NCERT, applying relevant law/formula with correct units and sign convention leads to It remains constant. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
In pure translational motion, all particles of the rigid body have the same velocity at any given instant, with no rotation involved. As per NCERT, applying relevant law/formula with correct units and sign convention leads to All particles have the same linear velocity. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
Angular acceleration (α) is caused by net external torque (τ = Iα), which drives rotational change. As per NCERT, applying relevant law/formula with correct units and sign convention leads to Net external torque. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
A rigid body is one where the distances between all pairs of particles remain constant, even under the influence of forces. This is an idealization, as real bodies deform slightly, but it’s a key assumption in rotational dynamics.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
For a rigid body rotating about a fixed axis, all particles have the same angular velocity, regardless of their distance from the axis, as it’s a property of the body’s rotation as a whole.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
Particles on the axis of rotation have a perpendicular distance r = 0 from the axis, so their linear velocity v = ωr = 0, meaning they remain stationary. As per NCERT, applying relevant law/formula with correct units and sign convention leads to They remain stationary. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
In theoretical mechanics, a rigid body is an idealization where inter-particle distances are fixed, preventing deformation and allowing focus on rotational and translational motion only. As per NCERT, applying relevant law/formula with correct units and sign convention leads to Because it is an idealization with fixed distances. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
Angular acceleration is zero when the net torque is zero (τ = Iα), as torque drives rotational change. As per NCERT, applying relevant law/formula with correct units and sign convention leads to Net torque is zero. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
The magnitude of torque (τ = rFsinθ) depends on the force magnitude F and the perpendicular distance rsinθ from the pivot to the line of action of the force. As per NCERT, applying relevant law/formula with correct units and sign convention leads to Force and perpendicular distance from the pivot. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
A force applied at the axis (r = 0) produces no torque (τ = rFsinθ = 0), so it cannot cause rotation about that axis. As per NCERT, applying relevant law/formula with correct units and sign convention leads to It causes no rotation. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
