Two equal balls having equal positive charge ‘q’ coulombs are susp

1.	Two equal balls having equal positive charge ‘q’ coulombs are suspended by two insulating strings of equal length. What would be the effect on the force when a plastic sheet is inserted between the two?
Answer» Force will decrease. Reason: Force between two charges each ‘q’ in vacuum is F₀ = \(\cfrac1{4\pi\varepsilon_0}.\cfrac{q^2}{r^2}\) On inserting a plastic sheet (a dielectric K > 1) Then F₀ = \(\cfrac1{4\pi\varepsilon_0}.\cfrac{q^2}{r^2}\) i.e, Force F = \(\cfrac{F_0}K\)

Two equal balls having equal positive charge ‘q’ coulombs are suspended by two insulating strings of equal length. What would be the effect on the force when a plastic sheet is inserted between the two?

Answer»

Force will decrease.

Reason: Force between two charges each ‘q’ in vacuum is F₀ = \(\cfrac1{4\pi\varepsilon_0}.\cfrac{q^2}{r^2}\)

On inserting a plastic sheet (a dielectric K > 1)

Then F₀ = \(\cfrac1{4\pi\varepsilon_0}.\cfrac{q^2}{r^2}\) i.e, Force F = \(\cfrac{F_0}K\)