Parallel Plate Capacitors Video Lessons

Concept

# Problem: A 2.0-cm-diameter parallel-plate capacitor with a spacing of 0.50 mm is charged to 200 V?Part A. What is the total energy stored in the electric field? Express your answer using two significant figures.U=______ Part B. What is the energy density. Express your answer using two significant figures.u = ________

###### FREE Expert Solution

The capacitance of a parallel plate capacitor:

$\overline{){\mathbf{C}}{\mathbf{=}}\frac{{\mathbf{\epsilon }}_{\mathbf{0}}\mathbf{A}}{\mathbf{d}}}$

Energy stored in a capacitor:

$\overline{){\mathbf{U}}{\mathbf{=}}\frac{{\mathbf{CV}}^{\mathbf{2}}}{\mathbf{2}}{\mathbf{=}}\frac{\mathbf{QV}}{\mathbf{2}}{\mathbf{=}}\frac{\mathbf{Q}}{\mathbf{2}\mathbf{C}}}$

(a)

d = 0.50 mm(1m/1000mm) = 5.0 × 10-4 m

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###### Problem Details

A 2.0-cm-diameter parallel-plate capacitor with a spacing of 0.50 mm is charged to 200 V?

Part A. What is the total energy stored in the electric field? Express your answer using two significant figures.

U=______

Part B. What is the energy density. Express your answer using two significant figures.

u = ________