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utkarshakash
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Homework Statement
A cone made of an insulating material has a total charge Q spread uniformly over its sloping surface. Calculate the energy required to bring a small test charge q from infinity to the apex A of the cone. The cone has a slope of length L.
Homework Equations
The Attempt at a Solution
Since work done equals change in P.E so I have to find the P.E of the system.
Suppose at a distance x from A I take an elementary cylinder of length dx. Let charge density be σ.
dQ=σdV
Wait! I don't know PE of disc and this seems an extremely time consuming process to me. Is there any other method?