REFRACTIVE INDEX OF GLASS PRISM measure with Glass Prism for std 11 & 12 GBSE

Refractive index of  Glass Prism

REFRACTIVE INDEX OF GLASS PRISM 

12.2  AIM :-

Using pins with a given prism determine the angles of deviation for six different values of angle of incidence. Draw the graph of angle of deviation versus angle of incidence. Determine, from this the angle of minimum deviation and using following formula determine refractive index of material of the prism.

Formula for Refractive index of Glass Prism

Angle of prism, A = ……. .

APPARATUS:  Glass Prism, Drawing paper, Drawing board, Pencil, Ruler, Pin, Protector,

FORMULA : - A + d = i + e

PROCEDURE :-

Take paper and pin it on Drawing board. 

Now take Glass prism and put it on center of Drawing board paper.

Mark the edges of the prism with pencil

Refractive index of  Glass Prism procedure

Draw N₁Q perpendicular to AB

Draw a line PQ making an angle i of 35^O with N₁Q

NOTE :- Pins should be 3 – 4 cm. away from each other.

Fix two pins vertically on line PQ  at point L & M.

Refractive index of  Glass Prism procedure

Place the prism in its original position.

Refraction takes place QR after placing prism on its original place

Now look from surface AC, adjust pin N & O vertically on the side which you are looking so that the images of the pins L & M and the pin N & O appear to be in the same straight line.

Refractive index of  Glass Prism procedure

Draw a line  SR

Measure d = Ð UDN

Refractive index of  Glass Prism procedure

Draw a line SR, and draw a perpendicular N₂R at R to the line AC

Measure  e (Angle of Deviation)

Refractive index of  Glass Prism procedure

Refractive index of  Glass Prism procedure

Note :- Repeat the experiment by taking different angles of incidence viz.,

 40 ⁰, 45 ⁰, 50 ⁰, 55 ⁰ and 60 ⁰.

For more details View Video

Angle of Deviation.