Force between charges and dielectrics

In summary, when a charge q is placed at x=-d and another charge q is placed at x=+d, the force between them is q^2/(4*pi*(eps_0)*4*d^2). When a dielectric with a constant K is inserted between -d/2 and d/2, the force remains the same. This is because the electric field E is not affected by the dielectric (K), and thus the force is the same as before.
  • #1
shomey
30
0
suppose I have a charge q at (x=-d) and a charge q at (x=+d).
the force between them is q^2/(4*pi*(eps_0)*4*d^2).

now, I insert a dielectric (K) between (-d/2<x<d/2), and try to calculate the force now...

it seems like it would be the same but it sounds strange...
If I use the D field, it is not effected by the dielectrics, and thus I can see that the electrical field E is the same as before (D/eps_0) and thus the force is the same...

could it be?
 
Physics news on Phys.org
  • #2
shomey said:
suppose I have a charge q at (x=-d) and a charge q at (x=+d).
the force between them is q^2/(4*pi*(eps_0)*4*d^2).

now, I insert a dielectric (K) between (-d/2<x<d/2), and try to calculate the force now...

it seems like it would be the same but it sounds strange...
If I use the D field, it is not effected by the dielectrics, and thus I can see that the electrical field E is the same as before (D/eps_0) and thus the force is the same...

could it be?


someone? please?
i really need help with this...
 
  • #3


Yes, it is possible for the force between two charges to remain the same even when a dielectric material is inserted between them. This is because dielectric materials do not conduct electricity, but rather they have a property called permittivity (represented by the symbol ε) which affects the electric field.

In this scenario, the permittivity of the dielectric material (represented by K) is likely greater than the permittivity of free space (represented by ε0). This means that the electric field between the two charges is reduced by a factor of K compared to when there was no dielectric present. However, since the distance between the charges (represented by d) has also decreased due to the presence of the dielectric, the overall force between the charges remains the same.

To understand this concept better, we can use the equation for electric field (E = F/q) and the equation for permittivity (D = εE) to see how the presence of the dielectric affects the force between the charges. When there is no dielectric, the electric field (E) is directly proportional to the force (F) and inversely proportional to the charge (q). However, when a dielectric is inserted, the electric field is reduced by a factor of K, but the permittivity (D) is also increased by the same factor. This means that the force remains the same because the change in electric field is offset by the change in permittivity.

In summary, the force between two charges can remain the same even when a dielectric material is inserted between them, as long as the permittivity of the dielectric is greater than that of free space and the distance between the charges is decreased. This concept is important in understanding the behavior of electric fields and forces in materials with different permittivities.
 

1. What is the force between two charges?

The force between two charges is determined by Coulomb's Law, which states that the force is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them.

2. How does the distance between two charges affect the force between them?

The force between two charges is inversely proportional to the square of the distance between them. This means that as the distance between the charges increases, the force between them decreases.

3. What is a dielectric material?

A dielectric material is an insulating material that can store electrical energy in the form of an electric field. Examples include rubber, glass, and plastic.

4. How does the presence of a dielectric material affect the force between charges?

The presence of a dielectric material between two charges decreases the force between them. This is because the dielectric material reduces the strength of the electric field, which in turn reduces the force between the charges.

5. Can the force between two charges be negative?

Yes, the force between two charges can be negative. This means that the charges are experiencing a repulsive force, and will move away from each other.

Similar threads

Replies
9
Views
1K
Replies
5
Views
825
Replies
2
Views
1K
Replies
5
Views
1K
Replies
3
Views
651
  • Electromagnetism
Replies
6
Views
767
Replies
4
Views
286
  • Electromagnetism
Replies
8
Views
877
  • Electromagnetism
Replies
4
Views
811
Replies
2
Views
823
Back
Top