Question

For a parallel-plate capacitor, the plate area is A = 110 mm², the plate separation is d = 2.5 mm, and the filling dielectric constant ε_r is 15.

(A) Calculate the capacitance of the capacitor: (Unit: pF)

(B) After connecting a 11 V battery across the capacitor, calculate E, D, Q, and the total stored electrostatic energy We.
(B1) Find the electric filed intensity (E) inside the capacitor: (Unit: V/m)

(B2) Find the electric flux density (D) inside the capacitor: (Unit: uC/(m*m))

(B3) Find the amount of charge (Q) accumulated on the surface of the top plate of the capacitor: (Unit: pC)

(B4) Find the electric energy (We) stored in this capacitor: (unit: pJ)

(C) With the source still connected, the dielectric is carefully withdrawn from between the plates. With the dielectric gone, re-calculate E, D, Q, and the energy stored in the capacitor.

(C1) With the dielectric gone, find the electric filed intensity (E) inside the capacitor: (Unit: V/m)

(C2) With the dielectric gone, find the electric flux density (D) inside the capacitor: (Unit: nC/(m*m))

(C3) With the dielectric gone, find the amount of charge (Q) accumulated on the surface of the top plate of the capacitor: (Unit: pC)

(C4) With the dielectric gone, find the electric energy (We) stored in this capacitor: (unit: pJ)