two charges are placed at a certain distance apart in vacuum if a glass slab is placed between them the force between them
Answer:
When two charges are placed at a certain distance apart in a vacuum, the force between them can be calculated using Coulomb’s law. However, if a glass slab is placed between them, the force between them can change due to the effect of the electric field of the glass slab on the charges.
The force between two charges q1 and q2 separated by a distance r in vacuum is given by Coulomb’s law as:
F = k * q1 * q2 / r^2
where k is the Coulomb’s constant.
When a glass slab is placed between the charges, the force between them depends on the relative permittivity (also known as dielectric constant) of the glass slab. The relative permittivity is a measure of how well a material can store electrical energy in an electric field, compared to a vacuum. The force between the charges can then be calculated using the formula:
F = k * q1 * q2 / (ε_r * r^2)
where ε_r is the relative permittivity of the glass slab.
Therefore, the force between the charges can decrease or increase based on the value of relative permittivity of the glass slab. If the relative permittivity of the glass slab is greater than 1, it is called a dielectric. In this case, the force between the charges decreases due to the electric field created by the dielectric. If the relative permittivity of the glass slab is less than 1, the force between the charges increases.
In conclusion, the force between two charges placed at a certain distance apart in vacuum changes when a glass slab is placed between them due to the effect of the electric field of the glass slab on the charges, which is determined by the relative permittivity of the glass slab.