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Discussion Response Post to: electrostatics

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Neeraj Agarwal (895)

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potential at center due to...
1) q is kq/x
2) 2q is k(2q)/x
Let new charge on sphere be 't' (after earthing)

potential at center due to sphere itself is kt/r

net potential should be 0 after earthing...so..

kq/x + 2kq/x + kt/r=0
=>3q/x + t/r=0
=> t= -3qr/x

so it acquires net -ve charge...this means some +ve charge has flown away from the sphere equal to +3qr/x

so answer should be (C)

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