The figure shows a surface XY separting two transparent media, medium-1 and medium-2. The lines ab and cd represent wavefronts of a light wave traveling in medium-1 and incident of XY. The lines ef and gh represent wavefronts of the light wave in medium-2 after refraction.
Speed of light is
the same in medium-1 and medium-2
larger in medium-1 and medium-2
larger in medium-2 than in medium-1
different at b and d