A particle of charge q and mass m is clamped rigidly at the

Last updated: 6/12/2023

A particle of charge q and mass m is clamped rigidly at the circumference of a ring with mass m and radius R Initially ring is in vertical plane resting on a sufficiently rough horizontal surface with charge q at the same horizontal level as that of the centre of the ring There exists uniform horizontal electric fields as shown 22 At t 0 the system is let free Given that qE mg 7 The magnitude of the friction force at t 0 is mg A mg B 2 mg Co 2 Work done by the electric field when the ring has rotated through 90 is 4 A mgR B 7mgR C mgR Speed of the centre of mass of the system after 90 rotation is W Rg 11 28 2 B Rg 28 C 4 Rg 28 D m R D mg 2R 9 m Sufficiently rough to avoid slipping D Rg E