The ratio of the radius of gyration of a thin uniform disc about an axis passing through its centre and normal to its plane to the radius of gyration of the disc about its diameter is:

The angular speed of a flywheel is increased from 600 rpm to 1200 rpm in 10 s. The number of revolutions completed by the flywheel during this time is:

If F = 6î - 3ȷ + 2k̂ is a force acting on a point P whose position vector with respect to origin is r = 2î + ȷ - k̂, then the torque τ acting on the point is: