Two conducting hollow spherical shells of radii R and 2R cerry charges -Q and 3Q respectively. How much charge will flow into the earth if inner shell is grounded ?

Explanation

When inner shell is grounded to the Earth then the potential of inner shell will become zero because potential of the Earth is taken to be zero.
`(Kx)/(R)+(K3Q)/(2R)=0`
`x=(-3Q)/2`, the charge that has increased
`=(-3Q)/2-(-Q)=(-Q)/2` hence charge flows into the Earth `=Q/2`