Find the dielectric constant of the medium?

In summary, the problem involves two point charges exerting a force in free space, which is later replaced by a homogeneous dielectric medium. The force decreases from 1.4∗10^−4 [N] to .9∗10^−4 [N] in the medium. The goal is to determine the dielectric constant ϵr of the medium and the key equation to use is E=F/Q.
  • #1
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Homework Statement


Two point charges a distance d apart in free space exert a force of 1.4∗10^−4 [N]. When the free space is replaced by a homogeneous dielectric medium, the force become .9∗10^−4 [N]. What is the dielectric constant ϵr of the medium?


Homework Equations


E=F/Q


The Attempt at a Solution


I have been staring at this problem for awhile. I can only think of using E=F/Q. But the problem is this only applies to free space and I do not know Q. So I am not sure where to start to compare the free space and medium.
 
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  • #2
The coulombic force in free space is k.q1.q2/r^2. In a medium, the value of k changes to k/dielectric constant. Now try to solve the question. :D
Hint : Compare the 2 values of electrostatic force.
 

1. What is the dielectric constant of a medium?

The dielectric constant, also known as the relative permittivity, is a measure of a material's ability to store electrical energy in an electric field. It is a dimensionless quantity that compares the amount of energy stored in the material to that stored in a vacuum.

2. How is the dielectric constant of a medium measured?

The dielectric constant can be measured by applying an electric field to a material and measuring the resulting displacement of charges. This can be done using a device called a capacitor, which consists of two conductive plates separated by a dielectric medium.

3. What factors affect the dielectric constant of a medium?

The dielectric constant of a medium is affected by the composition of the material, its temperature, and the strength and frequency of the electric field applied to it. In general, materials with higher concentrations of polar molecules or ions have higher dielectric constants.

4. Why is the dielectric constant important?

The dielectric constant is an important property in many fields, including electrical engineering, chemistry, and materials science. It is used to calculate the capacitance of a material, which is important in designing electronic devices such as capacitors and circuit boards. It also affects the behavior of materials in electric fields, such as in the polarization of molecules and the formation of electric double layers.

5. How does the dielectric constant of a medium affect the speed of light?

The dielectric constant of a medium affects the speed of light by determining how much the electric field is slowed down as it passes through the material. This is known as the refractive index of the material, and it is related to the dielectric constant. In general, materials with higher dielectric constants have higher refractive indices, meaning that light travels slower through them.

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