The periphery of an insulating disc of radius R and mass M

Last updated: 6/12/2023

The periphery of an insulating disc of radius R and mass M is charged uniformly and has linear charge density A The disc is rotating freely with constam angular velocity about a vertical axis as shown Uniform magnetic field B extends over entire circular region of disc pointing downward If the magnetic field is switched off then find the value c B for which the disc stops 1 2 40 M TAR 200 M R 0 M AR o B