AB is the incident ray on a glass slab.

  

The emergent ray is:

The path of a ray of light coming from air passing through a rectangular slab traced by four students are shown by figures P, Q, R and S. Which one of them is correct?

If you focus the image of a distant object, whose shape is given below, on a screen using a convex lens,

the shape of the image of this object on the screen would be:

The correct sequencing of angle of incidence, angle of emergence, angle of refraction and lateral displacement shown in the following diagram by digits $1, 2, 3$ and $4$ is:

A student very cautiously traces the path of a ray through a glass slab for different values of the angle of incidence ($\angle i$). He then measures the corresponding values of the angle of refraction ($\angle r$) and the angle of emergence ($\angle e$) for every value of the angle of incidence. On analysing these measurements of angles, his conclusion would be: