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EXPERIMENT 7

Aim

1. To verify Snells Law

2. To determine the refractive index of glass

Basic Theory

A certain light wave transports energy from one location to another and when it

hits a boundary plane between two different medium, then some of the energy will be

reflected by the boundary plane and stay in the initial medium.

Apparatus

Rectangular glass block

Ray box

White paper

Procedure

1. Place a rectangular glass block on the large of white paper and carefully

trace its outline.

2. Remove the glass block. Draw a normal line through a convenient point X.

3. Replace the glass block. Adjust the ray box so that the incident ray is

directed to point X with i = 40. Mark the emergent ray with two pencils crosses

P1 and P2.

4. Remove the glass block. draw a straight line through the points P1 and P2

unit it meets the outline of the block at Y. Join Y to X with straight line to

represent the refracted ray for i = 40, measure the angle of refraction r.

5. Repeat step 3 and 4 for i equal to 50,60,70,and 80.

6. Record your result in the table below.

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Result & Analysis Data

i r Sin i Sin r n=sin i/sin r

40 25 0,64 0,42 1,52

50 30 0,767 0,5 1,534

60 34 0,867 0,56 1,55

70 40 0,94 0,64 1,47

80 45 0,98 0,7 1,4

AVERAGE 1.49

Conclusion

a) The ratio of sin i is found to be 0.8388 = 1.487234 = 1,49

sin r 0.564

b) The refractive index of glass is 250, 300, 340, 400, and 450.

The experimenters :IL Rahma Pradira Gesari / X-5/ 13

Inayah Nur Utami / X-5/ 14

Khairina Izzati Amalia / X-5/ 15Konita Septiasti / X-5/ 16

Asessor: