Electromagnetic waves travel in a medium with a speed of  0.75×108m/s.The relative permeability of the medium  is 1. Find the relative permittivity.

we know that velocity em wave in a medium =V=Cμr∈r here V= Velocity of electromagnetic  wave in medium     C=Velocity of electromagnetic wave in vaccum   μr= relative permeability of the medium  ∈r= relative permittivity of the medium   ⇒∈r=C 2V2μr=3×108×3×1080.75×0.75×108×108×1=16