Electric field with dielectric constant

If a charge Q is on one plate and –Q is on the other, the potential difference between the plates is V = Ed.In summary, the conversation discusses two electrodes with a sheet of Mylar between them, attached to a 9.0 V battery. The Mylar is then withdrawn, but the electrode separation remains unchanged. The dielectric constant for Mylar is known to be 3.1. The question at hand is what the charges and electric field are before and after the Mylar is withdrawn. The formula for capacitance (C = k * epsilon_o * A / d) is used to find the charges, but the electric field is still difficult to determine. However, it is noted that the electric field is
  • #1
quietriot1006
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0

Homework Statement


Two 5.0mm*5.0mm electrodes with a 0.10mm thick sheet of Mylar between them are attached to a 9.0 V battery. Without disconnecting the battery, the Mylar is withdrawn. (Very small spacers keep the electrode separation unchanged.) Dielectric constant for Mylar is k=3.1. What is the charge before and after the Mylar is withdrawn?
What is the electric field before and after the mylar is withdrawn?

Homework Equations


C={k(epsilon_o)A}/d
Q=CV
C=kC_o


The Attempt at a Solution


I get the charges correctly but i just can't get the electric field before and after. Charge before is 62 pC and after its 20 pC. Help please.
 
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  • #2
The electric field E is uniform between the two "plates". There is a simple relation between V, E, and the distance d between the plates.
 

Related to Electric field with dielectric constant

1. What is an electric field?

An electric field is a physical quantity used to describe the effects of electrically charged objects on each other. It is a vector quantity, meaning it has both magnitude and direction.

2. What is dielectric constant?

Dielectric constant, also known as relative permittivity, is a measure of how well a material can store electrical energy in an electric field. It is a dimensionless quantity that is used to compare the ability of different materials to resist an electric field.

3. How does the dielectric constant affect the electric field?

The dielectric constant affects the electric field by reducing the strength of the field in a material. This is due to the polarization of the material's molecules in response to the electric field, which creates an opposing electric field that weakens the overall strength of the original field.

4. What is the relationship between dielectric constant and capacitance?

The dielectric constant and capacitance are directly proportional. This means that as the dielectric constant increases, the capacitance also increases. This is because a higher dielectric constant allows for a greater amount of electric charge to be stored in a material, leading to an increase in capacitance.

5. How is the electric field with dielectric constant calculated?

The electric field with dielectric constant is calculated using the equation E = V/d, where E is the electric field, V is the voltage, and d is the distance between the charged objects. The dielectric constant is also taken into account by multiplying it with the vacuum permittivity constant, ε₀, which is approximately 8.85 x 10^-12 C^2/Nm^2.

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