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The area of each plate of a parallel plate capacitor is 0.021 m2. The plates are 2.75 mm apart with a dielectric material (κ = 3.0) between them. The maximum possible electric field between the plates is 3.25 ✕ 105 V/m.What is the maximum energy that can be stored in the capacitor?

Respuesta :

Explanation:

The given data is as follows.

        Dielectric constant, K = 3.0

   Area of the plates (A) = 0.021 [tex]m^{2}[/tex]

   Distance between plates (d) = [tex]2.75 \times 10^{-3} m[/tex]

  Maximum electric field (E) = [tex]3.25 \times 10^{5} V/m[/tex]

Now, we will calculate the capacitance as follows.

             C = [tex]\frac{k \epsilon_{o} \times A}{d}[/tex]

                 = [tex]\frac{3.0 \times 8.85 \times 10^{-12} \times 0.021}{2.75 \times 10^{-3}}[/tex]

                 = [tex]\frac{0.55755 \times 10^{-12}}{2.75 \times 10^{-3}}[/tex]

                 = [tex]0.203 \times 10^{-9}[/tex] F

Formula to calculate electric charge is as follows.

               E = [tex]\frac{\sigma}{k \epsilon_{o}}[/tex]

or,           Q = [tex]E \times k \times \epsilon_{o}A[/tex]      (as [tex]\frac{\sigma}{\epsilon_{o}} = \frac{Q}{A}[/tex])

                   = [tex]3.25 \times 10^{5} \times 3.0 \times 8.85 \times 10^{-12} \times 0.021[/tex]

                   = [tex]181.2 \times 10^{-9} C[/tex]

Formula to calculate the energy is as follows.

                  U = [tex]\frac{1 \times Q^{2}}{2 \times C}[/tex]

                     = [tex]\frac{(181.2 \times 10^{-9} C)^{2}}{2 \times 1.6691 \times 10^{-9}}[/tex]

                     = [tex]\frac{32833.44 \times 10^{-18}}{3.3382 \times 10^{-9}}[/tex]

                     = [tex]9835.67 \times 10^{-9}[/tex]

or,                  = [tex]98.35 \times 10^{-7} J[/tex]

Thus, we can conclude that the maximum energy that can be stored in the capacitor is [tex]98.35 \times 10^{-7} J[/tex].