Alight wave traveling through medium 1 strikes a boundary with medium 2 at at a 45 degree angle. the light then enters the second medium and refracts toward the boundary. what would the two mediums be? 1. water air 2. diamond air 3. air glass 4. glass diamond

Here light ray strikes to interface at an angle of 45 degree and then refracts into other medium such that it will bend towards boundary.

So here the angle of incidence will be less than the angle of refraction as light moves towards the boundary after refraction which mean it will bend away from the normal

here it can be said that medium 2 will be rarer then medium 1

So here the possible options are

1. Water  

Air

2. Diamond  

Air

So in above two options medium 1 is denser and medium 2 is rarer

b.a device that inputs heat into a cool object