Question

A metal sphere of radius R is charged to a potential V. (a) Find the electrostatic energy stored in the electric field within a concentric sphere of radius 2R. (b) Show that the electrostatic field energy stored outside the sphere of radius 2R equals that stored within it.

Answer 1

Q = CV = 4πε₀R × V

E = 1/2q²/C

[∴ ‘C’ in a spherical shell = 4πε₀R]

[‘C’ of bigger shell = 4πε₀R]

Comments

Please recheck your answer. By your method, the answer comes to piERV^2. Where did the 2 come from?

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corrected