A parallel plate capacitor has an electrode area of 1000 mm^2, with a spacing of 0.1 mm between the electrodes. The dielectric between the plates is air with a permittivity of 8.85∗10^-12 F/m. The charge on the capacitor is 100 v. The stored energy in the capacitor is ____________(a) 44.3 J(b) 444.3 nJ(c) 88.6 nJ(d) 44.3 nJI got this question in an internship interview.This interesting question is from Singly Excited Electric Field Systems in section Basic Concepts in Rotating Machines of Electrical Machines

A parallel plate capacitor has an electrode area of 1000 mm^2, with a

1.	A parallel plate capacitor has an electrode area of 1000 mm^2, with a spacing of 0.1 mm between the electrodes. The dielectric between the plates is air with a permittivity of 8.85∗10^-12 F/m. The charge on the capacitor is 100 v. The stored energy in the capacitor is ____________(a) 44.3 J(b) 444.3 nJ(c) 88.6 nJ(d) 44.3 nJI got this question in an internship interview.This interesting question is from Singly Excited Electric Field Systems in section Basic Concepts in Rotating Machines of Electrical Machines
Answer» The CORRECT choice is (d) 44.3 nJ For EXPLANATION: WFLD = 1/2 q^2/C(X) C(x) = ε0A/x = 8.85∗10^-12∗100∗(10^-3)^2/0.1∗10^-3 = 8.85∗10^-12 F Wfld = 1/2∗Cv = 1/2∗100^2∗8.85∗10^-12 = 44.3nJ

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