Question

2 point charges repel each other with a force f when placed in water ofdielectric constant 81 wt will the force b/w them when placed the same distance apart in air

Answer 1

If some dielectric is present in the space between the charges, the net force acting on each charge is altered becuse charges are induced in the molecules of the intervening medium the force decreases K times.

                        

                                  F=   1    q1q2                                            (in vacuum )

                                       40  r2                                           

 

                              F’=      1     . q1q2                                         (in medium)

                                     40k     r2              

 

K is dielectric constant.

Hope this helps you.