A cylindrical capacitor is constructed using two coaxial cylinders of the same length 10cm of radii 2mm and 4mm. (a) calculate the capacitance (b) another capacitor of the same length is constructed with cylinders of radii 4mm and 8mm. Calculate the capacitance .

Explanation

(a) The capacitance of cyllindrical capacitor
` C = 2 pie eplision_0 l / 1 n (R_2 / R_1)`
`= 2 xx 3.14 xx 8.88 xx 10^(-12) xx 0.10 / 1n2`
`= 8 p F `
(b) The capacitance is same because ratio of radii is same . The rest form is also same,