Three plate capacitor and charge distribution

In summary, the figure given shows that the capacitance for two pairs is the same. The charge distribution across each plate depends on the connection to the battery terminals. Plates A and C, connected to the positive terminal, acquire positive charge while Plate B, connected to the negative terminal, acquires negative charge. The pair of capacitor plates should have opposite charges, with the negative charge on Plate B driving off negative charges from Plates A and C, leaving them positively charged.
  • #1
aashutosh
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In the figure given the capacitance for the two pair would be same. Can anybody please explain me how the charge would be distributed across each plate?
I think that the middle plate being isolated should have +Q on one side and -Q on other, but how would be the charge distribution about the remaining plates as both of them are connected to the positive terminal of the battery.
1.png
 
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  • #2
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A and C are connected to the positive terminal of the battery and acquire positive charge. B is connected to the negative terminal and acquire negative charge.
 
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Likes davenn
  • #3
zoki85 said:
?
A and C are connected to the positive terminal of the battery and acquire positive charge. B is connected to the negative terminal and acquire negative charge.
1.png
so will the charge distribution on the plates be as shown in the figure? If B is connected to the negative terminal then will both the sides of the plates will have -Q charge. But the pair of capacitor plates should have opposite charges right? Please i am a little confused with this. Correct me if i am wrong.
 
  • #4
aashutosh said:
so will the charge distribution on the plates be as shown in the figure? If B is connected to the negative terminal then will both the sides of the plates will have -Q charge. But the pair of capacitor plates should have opposite charges right? Please i am a little confused with this. Correct me if i am wrong.

no, Plates A and C are positively charged and Plate B is negatively charged

1a.GIF


Why would you expect it to be any different to this ?
you cannot get a excess negative charge on a plate connected to the battery positive ;)
Dave
 
Last edited:
  • #5
davenn said:
no, Plates A and C are positively charged and Plate B is negatively charged

View attachment 78672

Why would you expect it to be any different to this ?
you cannot get a excess negative charge on a plate connected to the battery positive ;)
Dave
Ok thank you. I thought that the capacitor plates should have + charge on one side and - on other side. May be i got confused.
 
  • #6
aashutosh said:
Ok thank you. I thought that the capacitor plates should have + charge on one side and - on other side. May be i got confused.

No Problems

Just consider that the negative charge on plate B is going to "drive off " ( repel) negative charges off plates A and C and thereby leaving them positively charged :)

Dave
 
  • #7
keep up the learning and questions
studying and learning about electronics and its related physics will keep you going for a lifetime
I have been at it for 40+ years and there's still so much I don't know haha ... its just such a huge subject
 

Related to Three plate capacitor and charge distribution

What is a three plate capacitor?

A three plate capacitor is a type of electrical component that consists of three parallel plates separated by insulating material. It is used to store electrical charge and has a capacitance value determined by the size and distance of the plates.

How does charge distribute in a three plate capacitor?

In a three plate capacitor, the charge distributes between the three plates according to their capacitance values. The plate with the highest capacitance will have the most charge, while the plate with the lowest capacitance will have the least charge. The distribution of charge is also affected by the voltage applied to the capacitor.

How do you calculate the capacitance of a three plate capacitor?

The capacitance of a three plate capacitor can be calculated using the formula C = εA/d, where C is the capacitance, ε is the permittivity of the insulating material between the plates, A is the area of the plates, and d is the distance between the plates.

What is the purpose of the third plate in a three plate capacitor?

The third plate in a three plate capacitor is used to increase the capacitance of the capacitor. By adding a third plate, the electric field between the two main plates is increased, resulting in a higher capacitance value.

How does a three plate capacitor differ from a standard two plate capacitor?

A three plate capacitor differs from a standard two plate capacitor in that it has an additional plate, resulting in a higher capacitance value and a different distribution of charge. The third plate also allows for more flexibility in the design and use of the capacitor.

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