Question

A cylindrical capacitor is made of two thin-walled concentric cylinders. The inner cylinder has radius , and the outer one a radius r2 = 8.0 mm. The common length of the cylinders is L = 150 m. What is the potential energy stored in this capacitor when a potential difference 4.0 V is applied between the inner and outer cylinder?

Answer 1

Answer:$9.6\times 10^{-8} J$

Explanation:

The capacitance of cylindrical capacitor is

C=$\frac{2\pi \varepsilon _0L}{\ln\frac{r_2}{r_1}}$

C=$\frac{2\pi \times 8.854\times 10^{-12}\times 150}{\ln\frac{8}{4}}$

C=$1.2\times 10^{-8} F$

potential Energy stored in capacitor=$\frac{1}{2}CV^2$

=$\frac{1}{2}\times 1.2\times 10^{-8}\times 4^2$

=$9.6\times 10^{-8} J$