Formula for electric field for capacitor and cylinder

In summary, the formula for electric field for a parallel plate capacitor is E = V/d and for a cylindrical capacitor is E = λ/2πεr. To calculate the electric field, plug in the values for potential difference, distance/charge density, and permittivity/radius. The main difference between the electric field for a capacitor and a cylinder is their geometry, resulting in different formulas. The electric field for a capacitor and cylinder cannot be the same, as they have different formulas and charge distributions. The electric field affects the behavior of electric charges by exerting a force on them, causing movement and electric current flow, with the strength depending on the distance between plates/cylinder and amount of charge.
  • #1
derek181
57
2
My prof gave two formulas without much explanation as to where he got them from. For a parallel plate capacitor he gave it as E=k2∏q/A and for a cylinder he gave E=kq2/Lr where L is the length of the cylinder and r is the radius and A is the area. Can someone please explain how he derived these.
 
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  • #2
hi derek181! :smile:

he gets it from the electric displacement field, D, which is always equal to the surface charge density, ie charge/area …

D = q/A or D = q/2πrL :wink:

(and see here)
 

1. What is the formula for electric field for a capacitor?

The formula for electric field for a parallel plate capacitor is E = V/d, where E is the electric field strength, V is the potential difference between the plates, and d is the distance between the plates. For a cylindrical capacitor, the formula is E = λ/2πεr, where λ is the linear charge density, ε is the permittivity of the material between the plates, and r is the radius of the cylinder.

2. How do you calculate the electric field for a capacitor?

To calculate the electric field for a capacitor, you can use the formula E = V/d or E = λ/2πεr, depending on the type of capacitor. Simply plug in the values for potential difference, distance/charge density, and permittivity/radius to get the electric field strength.

3. What is the difference between electric field for a capacitor and a cylinder?

The main difference between the electric field for a capacitor and a cylinder is the geometry of the two systems. A capacitor consists of two parallel plates, while a cylinder capacitor has a cylindrical shape. This difference in shape leads to different formulas for calculating the electric field strength.

4. Can the electric field for a capacitor and cylinder be the same?

No, the electric field for a capacitor and cylinder cannot be the same because they have different formulas for calculating the electric field strength. Additionally, the geometry and charge distribution of the two systems are different, resulting in different electric field strengths.

5. How does the electric field for a capacitor and cylinder affect the behavior of electric charges?

The electric field for a capacitor and cylinder affects the behavior of electric charges by exerting a force on them. This force causes the charges to move and leads to the flow of electric current. The amount of force experienced by the charges depends on the strength of the electric field, which is determined by the distance between the plates/cylinder and the amount of charge on them.

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