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Question
A point charge Q is placed at the origin. Find the electrostatic energy stored outside the sphere of radius R centred at the origin.
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Solution
Given :
Charge on the sphere = Q
Radius of the sphere = R
Capacitance of the sphere, C = 4πε0R
Thus, the energy of the sphere is given by
`E = 1/2 CV^2`
= `1/2 xx 4pi∈_0RC = Q_2/(4pi∈_0R)^2`
= `Q^2/(8pi∈_0R)`
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