The phenomenon of refraction of light depends on which of the following factors.

While tracing the path of ray of light passing from air through a rectangular glass slab, the setup, in which the best result will be obtained is

Four students reported the following observation tables for the experiment to trace the path of a ray of light passing through a glass slab for different angles of incidence. The observation likely to be correct are those of student.

A student does the experiment on tracing the path of a ray of light passing through a rectangular glass slab for different angles of incidence. He can get a correct measure of the angles of incidence and angles of emergence by following the label indicated in figure.

Beams of light are incident through the holes A and B and emerge out of box through the holes C and D respectively as shown in figure. Which of the following could be inside the box?

A student performs the experiment on tracing the path of ray of light passing through a rectangular glass slab for different angles of incidence. He measures the angle of incidence $\angle i$, angle refraction $\angle r$ and angle of emergence $\angle e$ for all his observations. He would find that in all cases.

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:

The path of a ray of light coming from air passing through a rectangular glass slab traced by four students are shown as A, B, C and D in figure. Which one of them is correct?

A concave lens made of a material of refractive index $n_1$ is kept in medium of refractive index $n_2$. A parallel beam light is incident on the lens. Complete the path of rays of light emerging from the concave lens if
  $$\begin{gathered} \left(i\right) n_1>n_2 \\ \left(ii\right) n_1=n_2 \\ \left(iii\right) n_1<n_2 \end{gathered}$$

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?