An electromagnetic wave travels in a medium with speed `2xx10^(2)` m/s. If relative permeability of medium is `1.0` then releative permitivity is

The speed of light of wavelength 6000overset(@)(A) in medium A is 0.8c. If the refractive index of medium B is 1.6, then calculte the refractive index of A relative to B.

Velocity of light in transparent medium is 2 xx 10^8 m/sec. Calculate the refractive index.