A very long insulating cylindrical shell of radius 6.40 cm carries charge of linear density 8.90μC/m spread uniformly over its outer surface. What would a voltmeter read if it were connected between the surface of the cylinder and a point 4.00 cmabove the surface?(adsbygoogle = window.adsbygoogle || []).push({});

λ=dq/dr

V=k∫dq/r

V=λk*ln([r+x]/r)

V=(8.9e-6)*9e9*ln(.104/.064)

V=3.89e4

The actual answer is 7.78e4 (twice my answer). I can't figure out whats wrong with my integral to make the answer half of what it should be. Thanks!

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# Homework Help: Cylindrical shell- electric potential problem

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