Question

A student has to trace the path of a ray of light passing through a rectangular glass slab for four different values of angle of incidence .
(A) write two important precaution for this experiment .
(B) list two conclusion the student will draw based on his experiment .

Answer 1

Hey pudding,

              you would have studied about this refraction of light through a rectangular glass slab, which is far easier than a triangular prism. You see, three is a powerful number. Anyways coming to point, the refraction of light in  a triangular prism looks something like this !!

It took my poor painting knowledge a long time to complete the diagram on a PC.

So, the precautions are,

• The refracting faces of the glass prism should be ensured that they are smooth, transparent and without any air bubble or broken edge. It's unfit for this experiment.
• The student has to use a sharp pencil to draw boundary of the prism and rays.
• The angle of incidence should be between 30 degrees and 60 degrees.

These are my favourite  three points, as I said three is a powerful number.

The conclusion can be given that,

1. As the angle of incidence increases gradually, the angle of deviation decreases.
2. They both are inversely proportional.