Angle of Incidence, Angle of image through Glass Slab experiments for std 8 to 12

To draw the path of a ray passing through a glass slab and, hence, to measure the angle of incidence and the angle of image.

AIM : To draw the path of a ray passing through a glass slab and, hence, to measure the angle of incidence and the angle of image.

PRINCIPLE :     When an oblique ray of light enters from one      transparent medium to another transparent medium,  at the surface separating these two media, the light  ray changes its path. This phenomenon is called  refraction of light. When a ray of light passes through  a glass-slab, it is refracted twice, as a result of which, the emergent ray becomes parallel to the incident ray.

APPARATUS :   Glass –slab, Drawing-board, Drawing paper (White),  Foot-rule, Pencil, Pins, Push pins and Protractor.

Paper fit with pins and set Glass Slab

Ø  Fix a white drawing-paper on the drawing board using push pins.  Now place the glass-slab on it and mark its position PQRS by drawing its out-line using a pencil.

Draw Ray AB not perpendicular to PQ

Ø  Now draw a ray AB such that it is not perpendicular to PQ. Fix two pins upright with separation of 2-3 cm on this ray.

See Image from another side and set P3 P4

Ø    Now try to see the images of P₁ and P₂ from side RS and fix pins P₃  and P₄ upright so that images of P₁ and P₂ and pins P₃ and P₄ become collinear at their lower ends.

Remove pins and Glass slab

Ø  Now remove the slab and the pins obtain emergent ray CD by drawing a line passing through marks of P₃ and P₄, which intersects RS at C.

Ø  Join  B and C to complete the path of the ray. Now draw a normal MN to the surface PQ in such a way that it passes through B. Also       draw M’N’, through C to the surface RS.

Measure Angle of Incidence and Angle of Emergence.

Ø  Measure ÐAMB (Angle of Incidence) and ÐOCN’ (Angle of Emergence).

By changing Angle of Incidence repeat the experiment

Ø  Repeat the experiment for various values of angle of incidence AMB and note your observations in the table.

Angle of Incidence Video

Angle of Incidence, Emergence, Refraction through glass slab.wmv

    

Angle of Prism, Physics practical for the standard 12

REFRACTIVE INDEX OF PRISM

AIM:-

Determine with the help of pins, the angle of the given glass prism. Determine the values of angle of emergence and angle of deviation for four different values of angle of incidence. Hence prove that i + e = A +d.

PRINCIPLE :

Reflection and refraction of light.

PRECAUTIONS
 While marking the position of a prism with pencil, the prism should not be disturbed. 
A prism should be carefully put back exactly at the marked position. 
While pressing the heads of the pins for fixing them use metal coin or a hard object so that you do not hurt your palm. 
Do not press the pins very hard in the board otherwise it becomes difficult to remove them afterwards. 
See that the pins pushed in the board remain perpendicular to the board.

Angle of Prism 

Angle of Prism Conclusion

REFRACTIVE INDEX OF PRISM

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.

Angle of Prism Formula

Angle of prism, A = ……. .

Angle of Deviation measure

Angle of Deviation

Angle of Deviation Observation table  

Angle of Deviation Graph