If two charges \( q_1 \) & \( q_2 \) are separated with distance ‘\( d \)’ and placed in a medium of dielectric constant \( K \). What will be the equivalent distance between charges in air for the same electrostatic force?
\( k\sqrt{d} \)
\( 2d\sqrt{k} \)
\( 1.5d\sqrt{k} \)
\( d\sqrt{k} \)