JEE Main | 2014Rotational MotionMedium
Question
A bob of mass m attached to an inextensible string of length l is suspended from a vertical support. The bob rotates in a horizontal circle with an angular speed ω rad/s about the vertical. About the point of suspension
Options
A.Angular momentum is conserved
B.Angular momentum changes in magnitude but not in direction
C.Angular momentum changes in direction but not in magnitude
D.Angular momentum changes both in direction and magnitude
Solution

τ = mg × l sin θ. (Direction parallel to plane of rotation of particle)
as τ is perpendicular to
, direction of L changes but magnitude remains same.Create a free account to view solution
View Solution FreeMore Rotational Motion Questions
The wheels of moving vehicles are made hollow in the middle and thick at the periphery, because...In the adjoining figure along which axis the moment of inertia of the triangular lamina will be maximum- [Given that AB ...Two circular discs of radius each 10 cm are joined at their centres by a rod of length 30 cm and mass 600 gm as shown in...Two solid spheres are made of the same material. The ratio of their diameters in 1 : 2. The ratio of their moments of in...A solid sphere is rotating in free space. If the radius of the sphere is increased keeping mass same which one of the fo...