question_answer

Force between two point charges kept at a distant d apart in air is F. If these charges are kept at the same distance in water, how does the electric force between them change?               

Answer:

                Dielectric constant for water, is \[\kappa =80\]                 \[\therefore \,\,\,{{F}_{water}}=\frac{{{F}_{air}}}{\kappa }=\frac{F}{80}.\] Thus the force in water is \[1/80\] times the original force in air.