Question

Two charged spheres separated by a distance ${}^{\prime }{d}^{\prime }$ exert some force on each other. If they are immersed in a liquid of dielectric constant $2$, then what is the force exerted, if all other conditions are same?

• A. F/2
• B. F
• C. 2F
• D. 4F

Answer 1

Answer: (A)

Given : Distance between two charges $=d$.
and dielectric constant $(k)=2$. Force between two charged spheres $(F)=\frac{1}{4\pi {\epsilon }_0}\times \frac{q_1{q}_2}{r_2}$, where ${\epsilon }_0$ is
permitivity of free space. and force for a medium wit dielectric constant $k$
$F^{\prime }=\frac{1}{k}\times \frac{1}{4\pi {\epsilon }_0}\times \frac{q_1{q}_2}{r_2}=\frac{F}{k}=\frac{F}{2}$