दिया है -
l = 15 सेमी = 0 .15 मी , ` q = 3 .5 mu C = 0 .13 xx10^(-6)C `
a = 1.4 सेमी = ` 1.4xx10^(-2)` मी ,
b = 1.5 सेमी `=1.5 xx10^(-2)` मी
सूत्र - `C = (2piin_(0)l)/(log b//a) = (l)/(2xx(1)/(4piin_(0))xx2.303log_(10)b//a)`
` (0.15)/(2xx9xx10^(9)xx2.303log_(10) ((0.015)/(0.014)))`
` = (0.15xx10^(-9))/(18xx2.303xx0.03)`
` = 0.1206xx10^(-9) F = 1.2xx10&^(-10) F .`
तथा विभव ` V = (q)/(C) = (3.5xx10^(-6))/(1.2xx10^(-10)) = 2.9xx10^(4)` वोल्ट