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(b)Total changedistributed on the sphevical shell =QSurface charge density is sigma=(" change ")/(" Area ") :.sigma=(Q)/(4piR^(2)) frequency of revolution =f Angular veloity of spherer omega=2 inf :' Since sphere is rotated an axis passes throug z-axis vec(omega)=omega hat(z)Using spherical polar co-ordinates (rho,phi,theta). with origine at the centre of the spheriecal shell,consider small-area element ds of the ring of rodius gamma Located at distance R from the origine on the surface of sphere.vec(gamma)=R sin theta hat(gamma)co-ordinate e=R is constantiforeach elemental area.dq=sigma*ds=sigmaR^(2)sin theta d theta d phicurrent in the ring is given by{:[dI=(dq)xx f=(sigmaR^(2)sin theta*d theta d phi)xx(omega)/(2pi)],[=>dI=(omega sigmaR^(2)sin theta d theta d phi)/(2pi)]:}Magnetic dopole moment of thering is given byd ... See the full answer