A Cylindrical Capacitor Is Made of Two Thin-Walled Concentric Cylinders

Multiple Choice

A cylindrical capacitor is made of two thin-walled concentric cylinders. The inner cylinder has radius r₁ = 4.0 mm, 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? (k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C²)

A) 9.6 × 10^-8 J
B) 1.3 × 10^-8 J
C) 6.3 × 10^-8 J
D) 0.34 × 10^-8 J
E) 4.6 × 10^-8 J