Very large capacitors have been considered as a means for storing electrical energy.If we constructed a very large parallel-plate capacitor of plate area 10 m² using paper (κ = 3.7)of thickness 1.0 mm as a dielectric,how much electrical energy would it store at a plate voltage of 5000 V? (ε₀ = 8.85 × 10−¹² C²/N⋅m²) A) 4.1 J B) 8200 J C) 0.41 J D) 82,000 J

Question

Quizplus · Accepted Answer

The capacitance C of a parallel-plate capacitor is given by C = κε₀A/d. Substituting the given values, C = (3.7)(8.85 × 10⁻¹² C²/N⋅m²)(10 m²)/(0.001 m) = 3.27 × 10⁻⁷ F. The energy stored is given by U = 0.5CV². Substituting the values, U = 0.5(3.27 × 10⁻⁷ F)(5000 V)² = 4.1 J.

Very Large Capacitors Have Been Considered as a Means for Storing