When air is replaced by a dielectric medium of constant K, the maximum force separated by a distance

Options

A. increases `K^(-1)` times
B. increases K times
C. decreases K times
D. remains constant

Answer

C

Explanation

From Coulomb.s law theforce of attraction between two charges `q_(1)` and `q_(2)` separated by a distance r given by
`F=1/(4pi epsilon_(0)) . (q_(1)q_(2))/(r^(2))`
Where `epsilon_(0)` is the absolute permittivity of the material medium.
For air `epsilon=epsilon_(0)` and for all other materials
`F=1/(4 pi epsilon_(0)K)(q_(1)q_(2))/(r^(2))`
For all electric the value of K is greaer than 1, thus, if some dielectric between the charges, then the force betweem them decreases K times.