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A sheet of gold foil (negligible thickness) is placed between the plates of a capacitor and has the same area as each of the plates. The foil is parallel to the plates, at a position 1/2 of the way from one to the other. Before the foil is inserted, the capacitance is 7.9μF. What is the capacitance after the foil is in place?

What I tried:

distance 1 (d1) = 1/2 + 1/2 (d) = 1 d

distance 2 (d2) = 1/2 d

C1 = EA/d C2 = EA/ 0.5d

1/Cs = 1/C1 + 1/C2

= 1/ (EA/d) + 1/ (EA/0.5d)

= 3d/ EA

Since 1/ Co = d/EA

1/Cs = 3/ 7.9

Cs = 2.633

Is this right please?

What I tried:

distance 1 (d1) = 1/2 + 1/2 (d) = 1 d

distance 2 (d2) = 1/2 d

C1 = EA/d C2 = EA/ 0.5d

1/Cs = 1/C1 + 1/C2

= 1/ (EA/d) + 1/ (EA/0.5d)

= 3d/ EA

Since 1/ Co = d/EA

1/Cs = 3/ 7.9

Cs = 2.633

Is this right please?

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