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 1.0 m² using paper (k = 3.7)of thickness 1.0 mm as a dielectric,how much electrical energy would it store at a plate voltage of 5 000 V? (e₀ = 8.85 x 10^-12 C²/N*m²) A)0.41 J B)90 J C)9 000 J D)45 000 J

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Quizplus · Accepted Answer

The energy stored in a capacitor is given by the formula $ U = \frac{1}{2} C V^2 $. The capacitance $ C $ of a parallel-plate capacitor is $ C = \frac{k \cdot \epsilon_0 \cdot A}{d} $. Substituting the given values, $ C = \frac{3.7 \cdot 8.85 \times 10^{-12} \cdot 1.0}{0.001} $. Then, $ U = \frac{1}{2} \cdot C \cdot (5000)^2 $. Calculating this gives approximately 0.41 J.

Very Large Capacitors Have Been Considered as a Means for Storing