Question

draw a neat labelled diagram and explain the refraction of light through a triangular glass prism

Answer 1

To observe the refraction of light through a glass prism, we can perform the following activity.

Take a triangular glass prism, paper sheet, and a few drawing pins. Fix the sheet on a drawing board with the help of drawing pins. Now, place the glass prism on the sheet and draw the outline MNP of the prism on the sheet (as shown in the figure). Draw a straight line AB on the sheet in such a way that it makes some angle with the face MN of the prism. Now, fix two pins on this line and mark them as R and S respectively.



Now, observe the pins R and S through the other side of the prism. Move your head laterally to see the two pins R and S in a straight line. Fix a pin on the sheet near the prism on your side and mark it as T.

Repeat the same step and try to observe the three pins R, S, and T in a straight line. Fix another pin on the sheet so that all four pins appear to be in a straight line when looked through the prism. Draw a straight line CD that passes through the third and the fourth pin i.e., T and W respectively (see figure).



Now, remove the prism and join points B and C. The straight line AB, BC, and CDshows the path of the light ray. It is clear that the path of light is not a straight line since light bends towards the base NP.



What causes the light to bend when passed through a prism?

Light bends because of refraction that takes place at points B and C respectively, when it tries to enter and emerge from the prism.

Now, draw a straight line normal to side MN and let it pass through point B. Similarly, draw a straight linenormal to side MP and let it pass through point C.

Here, line AB = Incident ray

Line BC = Refracted ray

Line CD = Emergent ray

Angle i = Angle of incidence

Angle r = Angle of refraction

Angle e = Angle of emergence

Angle= Angle of deviation

HOPE THIS HELPZ.....