Question

The force between two point charges placed in a material medium of dielectric constant $\varepsilon_{r}$ is $F$.If the material is removed, then the force between them becomes

• A. $\varepsilon_{r} F$
• B. $\varepsilon F$
• C. $\frac{F}{\varepsilon_{r}}$
• D. $\frac{\varepsilon}{F}$
• E. $\varepsilon_{0 }F$

Answer 1

Answer: (A)

Dielectric constant of medium $=\varepsilon_{r}$
Force $=F$
The electric force between point charges in the presence of medium is given by
$F_{\text {medium }} =\frac{F_{\text {air }}}{\varepsilon_{r}} $
$F_{\text {air }} =F_{m} \times \varepsilon_{r}=F \cdot \varepsilon_{r}$