Respond to the question below.
 
Draw a ray diagram showing refraction of light through a rectangular glass slab. Explain the changes observed when light enters and leaves the slab.
 
At the first surface (air-glass interface), the light ray enters from air into glass and .
 
Inside the glass slab, the ray travels in a through the transparent medium.
 
At the second surface (glass-air interface), the ray bends .