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

Answer: (B)

K : 1

Answer 2

$F_{a} = \frac{q_{1}q_{2}}{4\pi\varepsilon_{0}r^{2}},F_{b} = \frac{q_{1}q_{2}}{K4\pi\varepsilon_{0}r^{2}}$ ⇒ $F_{a}:F_{b} = K:1$