$-----$What is the linear charge density of a thin wire bent into a circle $($or ring$)$ of radius $6\mathrm{.}72$ cm if the total charge on the wire is $2\mathrm{.}94$ MC$?$ Give your answer in MC$/$m$.$D

$----$Question $4$ A circular metal plate of radius $18\mathrm{.}7$ cm carries a total charge of $5\mathrm{.}08$ MC and the charge is distributed uniformly over the surface of the plate. Determine the surface charge density on the plate and report your answer in $4$C$/$m$?.$