Please show all work. I am having trouble with these and I don\'t know if I am r

Question

Please show all work. I am having trouble with these and I don't know if I am right, please help asap!

a) A parallel plate capacitor of capacitance C0 has plates of area A with separation d between them. When it is connected to a battery of voltage V0, it has charge of magnitude Q0 on its plates. It is then disconnected from the battery and the plates are pulled apart to a separation 2d without discharging them. After the plates are 2d apart, the new capacitance and the potential difference between the plates are:

a.

½C0, ½V0

b.

C0, 2V0

c.

½C0, V0

d.

2C0, 2V0

e.

½C0, 2V0

b) A parallel-plate capacitor of area A and spacing d is filled with three dielectrics as shown. Each occupies 1/3 of the volume. What is the capacitance of this system?

c) This capacitor is now filled as shown. Each occupies 1/3 of the volume. What is the capacitance of this system?

d) Use Gauss's law to find the field in each dielectric, and then calculate ?V across the entire capacitor.

a.

½C0, ½V0

b.

C0, 2V0

c.

½C0, V0

d.

2C0, 2V0

e.

½C0, 2V0

Explanation / Answer

a)
Q0 will not chnage since we are not adding or removing charge
Q' = Q0
Capacitance= ebsoleneo*A/d
C' = C0/2

V'= Q'/C'
= Q0/C0/2
=2* Q0/C0
= 2*V0
Answer: e

b)
Its like 3 capacitors in parallel
C1 = k1 * ebsoleneo *A / (3d)
C2 =k2 * ebsoleneo *A / (3d)
C3 =k3 * ebsoleneo *A / (3d)

Cnet = C1+C2+C3
=(k1+k2+k3)*ebsoleneo *A/(3*d)
c)
Its like 3 capacitors in series
C1 = k1 * ebsoleneo *A / (d/3)
= 3*k1*ebsoleneo *A/d
C2 = k2 * ebsoleneo *A / (d/3)
= 3*k2*ebsoleneo *A/d
C3 = k3 * ebsoleneo *A / (d/3)
= 3*k3*ebsoleneo *A/d

1/Cnet = 1/C1 + 1/C2 + 1/C3
find Cnet

d)
which capacitor you are talkking about

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