Question

The ratio of the forces between two small spheres with constant charge (a) in air (b) in a medium of dielectric constant K is

• A. 1 : K
• B. K : 1
• C. $1:K^2$
• D. $K^2:1$

Answer 1

The correct option is B K : 1

$F_a=\frac{q_1{q}_2}{4\pi {\epsilon }_0{r}^2},F_b=\frac{q_1{q}_2}{K4\pi {\epsilon }_0{r}^2},\Rightarrow F_a:F_b=K:1$